dockerfile: install osbuild-composer-core

This no longer pulls in systemd/worker, saving space and makes it
suitable for use in a UBI container, where qemu-img is not available.

This drops support for --inbuilt-worker from entrypoint.py. The script
could be simplified further in a future commit, or folded into the
main binary.

containers/osbuild-composer/Dockerfile

@@ -43,7 +43,7 @@ RUN \
                         "--repofrompath=ephemeral0,${OSB_RPMREPO}" \
                         "--setopt=ephemeral0.gpgcheck=0" \
                         "--setopt=ephemeral0.priority=10" \
-                        install "osbuild-composer" \
+                        install "osbuild-composer-core" \
                 && dnf clean all
 
 # Copy all our local sources, so we can access them from within the container

containers/osbuild-composer/entrypoint.py

@@ -32,20 +32,6 @@ class Cli(contextlib.AbstractContextManager):
             prog="container/osbuild-composer",
         )
 
-        # --[no-]builtin-worker
-        self._parser.add_argument(
-            "--builtin-worker",
-            action="store_true",
-            dest="builtin_worker",
-            help="Enable built-in local worker",
-        )
-        self._parser.add_argument(
-            "--no-builtin-worker",
-            action="store_false",
-            dest="builtin_worker",
-            help="Disable built-in local worker",
-        )
-
         # --[no-]composer-api
         self._parser.add_argument(
             "--composer-api",