dnf-json: avoid randomizing package order

We want depsolving via dnf-json, followed by rpm installation to be
the same as installing directly with dnf. However, the `install_set()`
helper we used inserts the list of packgaes into a set internally
before returning it to us to iterate. Set order iteration is not
a FIFO in python, and because the order of package installation
in rpm is only a partial order, we ended up with different images
depending on whether we installed through dnf or dircetly via rpm.

To avoid the indirection via a set, open-code `install_set()` without
the intermediate allocation.

Signed-off-by: Tom Gundersen <teg@jklm.no>

dnf-json

@@ -129,7 +129,12 @@ with tempfile.TemporaryDirectory() as persistdir:
             exit_with_dnf_error("DepsolveError", f"There was a problem depsolving {arguments['package-specs']}: {e}")
 
         dependencies = []
-        for package in base.transaction.install_set:
+        for tsi in base.transaction:
+            # avoid using the install_set() helper, as it does not guarantee a stable order
+            if tsi.action not in dnf.transaction.FORWARD_ACTIONS:
+                continue
+            package = tsi.pkg
+
             dependencies.append({
                 "name": package.name,
                 "epoch": package.epoch,