Revert "runners: clean up temp files before exiting the runner"

This reverts commit bc04bfc366.

The `remove_tmpfiles()` helper is nice but it is also problematic
because it creates extra output after the command was run and
created output. E.g. a test failure on centos stream9 [0]
```
            r = root.run(["stat", "--format=%a", "/var/tmp"], monitor)
            assert r.returncode == 0
>           assert r.stdout.strip().split("\n")[-1] == "1777"
E           AssertionError: assert '/usr/lib/tmp... such process' == '1777'
E
E             - 1777
E             + /usr/lib/tmpfiles.d/rpcbind.conf:2: Failed to resolve user 'rpc': No such process
```
Here the output from "stat" is not the last output because the
rempve_tmpfiles runs `systemd-tmpfiles --clean --remove` which
produces some noisy output after stat was run.

This was found by @thozza (thanks!) and discussed in osbuild PR#1785.

There are various ways to fix this, the one is to use the
`--graceful` option of systemd-tmpfiles. However that only got added in
systemd v256 and centos-stream9 has v252 so that is sadly not an option.

Plus even when avaialble it will produce some informational output like
```
All rules containing unresolvable specifiers will be skipped.
```

Another way would be to sent the output from systemd-tmpfiles cleanup
to /dev/null. Not really great as we will not know about real problems
or warnings that we should care about.

None of the option above is good. So I started looking at the tmpfiles.d
rules and the cleanup and why we are doing it. It was added relatively
recently in https://github.com/osbuild/osbuild/pull/1458 and after
some medidiation not having it seems to do no harm (details below). The
tl;dr is that the buildroot is created inside bubblewrap and the
dirs that `--clean` and `--remove` touch are already tmpdirs created
just for the buildroot so the cleanup in the runner is redundant
(and because the cleanup is now run for each buidlroot.run() command
there *might* be unintended conequences but the current rules seem
to not have any).

In detail, the tmpfiles_cleanup() does two things:
1. `--clean`
It will remove files that are older then the given age
in tmpfiles.d. The tmpfiles in centos9 give me the following ages:
```
$ systemd-tmpfiles --cat-config|grep -E '[0-9]+d$'
d /var/lib/systemd/pstore 0755 root root 14d
d /var/lib/systemd/coredump 0755 root root 3d
q /tmp 1777 root root 10d
q /var/tmp 1777 root root 30d
D! /tmp/.X11-unix 1777 root root 10d
D! /tmp/.ICE-unix 1777 root root 10d
D! /tmp/.XIM-unix 1777 root root 10d
D! /tmp/.font-unix 1777 root root 10d
```
Given that we run our commands inside a bubblewrap environment and
give it a fresh /run, /tmp, /var [1] there really should be no long
lived things and even if there are they are cleaned up from the
buildroot itself

2. `--remove`
It will remove files marked for removal in tmpdfiles.d. Running
it on a centos9 env it yields for me:
```
$ systemd-tmpfiles --cat-config|grep -E '^[rRD]'
R /var/tmp/dnf*/locks/*
r /var/cache/dnf/download_lock.pid
r /var/cache/dnf/metadata_lock.pid
r /var/lib/dnf/rpmdb_lock.pid
r /var/log/log_lock.pid
r! /forcefsck
r! /fastboot
r! /forcequotacheck
D! /var/lib/containers/storage/tmp 0700 root root
D! /run/podman 0700 root root
D! /var/lib/cni/networks
R! /var/tmp/container_images*
D     /run/rpcbind 0700  rpc  rpc  -  -
D /run/sudo/ts 0700 root root
R! /tmp/systemd-private-*
R! /var/tmp/systemd-private-*
r! /var/lib/systemd/coredump/.#*
D! /tmp/.X11-unix 1777 root root 10d
D! /tmp/.ICE-unix 1777 root root 10d
D! /tmp/.XIM-unix 1777 root root 10d
D! /tmp/.font-unix 1777 root root 10d
r! /tmp/.X[0-9]*-lock
```
which is also covered by the bwrap cleanup.

[0] https://artifacts.dev.testing-farm.io/2d07b8f3-5f52-4e61-b1fa-5328a0ff1058/#artifacts-/plans/unit-tests
[1] https://github.com/osbuild/osbuild/blob/main/osbuild/buildroot.py#L218

osbuild/util/runners.py

@@ -62,10 +62,6 @@ def tmpfiles():
     subprocess.run(["systemd-tmpfiles", "--create"], check=False)
 
 
-def remove_tmpfiles():
-    subprocess.run(["systemd-tmpfiles", "--clean", "--remove"], check=False)
-
-
 def nsswitch():
     # the default behavior is fine, but using nss-resolve does not
     # necessarily work in a non-booted container, so make sure that
@@ -94,8 +90,7 @@ def sequoia():
     # images).
     os.makedirs("/etc/crypto-policies", exist_ok=True)
     shutil.copytree(
-        "/usr/share/crypto-policies/back-ends/DEFAULT",
-        "/etc/crypto-policies/back-ends"
+        "/usr/share/crypto-policies/back-ends/DEFAULT", "/etc/crypto-policies/back-ends"
     )
 
 

runners/org.osbuild.centos9

@@ -14,6 +14,5 @@ if __name__ == "__main__":
             runners.tmpfiles()
             runners.nsswitch()
             r = subprocess.run(sys.argv[1:], check=False)
-            runners.remove_tmpfiles()
 
         sys.exit(r.returncode)

runners/org.osbuild.fedora30

@@ -14,6 +14,5 @@ if __name__ == "__main__":
             runners.tmpfiles()
             runners.nsswitch()
             r = subprocess.run(sys.argv[1:], check=False)
-            runners.remove_tmpfiles()
 
         sys.exit(r.returncode)

runners/org.osbuild.fedora38

@@ -15,6 +15,5 @@ if __name__ == "__main__":
             runners.nsswitch()
             runners.sequoia()
             r = subprocess.run(sys.argv[1:], check=False)
-            runners.remove_tmpfiles()
 
         sys.exit(r.returncode)

runners/org.osbuild.rhel81

@@ -41,6 +41,5 @@ if __name__ == "__main__":
             os_release()
             runners.python_alternatives()
             r = subprocess.run(sys.argv[1:], check=False)
-            runners.remove_tmpfiles()
 
         sys.exit(r.returncode)

runners/org.osbuild.rhel82

@@ -16,6 +16,5 @@ if __name__ == "__main__":
             runners.python_alternatives()
             env = runners.quirks()
             r = subprocess.run(sys.argv[1:], env=env, check=False)
-            runners.remove_tmpfiles()
 
         sys.exit(r.returncode)