ci: use container-rpmbuilder image (#186)

CI images move off the packer-images monorepo to semver-released container-* repos.

- run CI steps on docker-internal/rpmbuilder:0.1.0-<distro>
- build el9 packages from docker-internal/rpmbuilder:0.1.0-alma9

Reviewed-on: #186
Co-authored-by: unkin-agent <unkin-agent@unkin.net>
Co-committed-by: unkin-agent <unkin-agent@unkin.net>

tools/build

@@ -753,7 +753,7 @@ def get_base_image_from_metadata(package_dir: Path, distro: str = "el/9") -> str
         Base image URL or default if not found
     """
     metadata_file = package_dir / "metadata.yaml"
-    default_image = "git.unkin.net/unkin/almalinux9-rpmbuilder:latest"
+    default_image = "artifactapi.k8s.syd1.au.unkin.net/docker-internal/rpmbuilder:0.1.0-alma9"
 
     if not metadata_file.exists():
         return default_image
@@ -784,7 +784,7 @@ def build_package_docker(
     package_release: str,
     dist_dir: Path,
     repository: str,
-    base_image: str = "git.unkin.net/unkin/almalinux9-rpmbuilder:latest",
+    base_image: str = "artifactapi.k8s.syd1.au.unkin.net/docker-internal/rpmbuilder:0.1.0-alma9",
     dry_run: bool = False
 ) -> bool:
     """
@@ -1066,7 +1066,7 @@ def build_package_buildah(
     package_release: str,
     dist_dir: Path,
     repository: str,
-    base_image: str = "git.unkin.net/unkin/almalinux9-rpmbuilder:latest",
+    base_image: str = "artifactapi.k8s.syd1.au.unkin.net/docker-internal/rpmbuilder:0.1.0-alma9",
     dry_run: bool = False
 ) -> bool:
     """
@@ -1263,7 +1263,7 @@ class PackageInfo:
     release: str
     directory: Path
     distro: str = 'almalinux/el9'
-    base_image: str = "git.unkin.net/unkin/almalinux9-rpmbuilder:latest"
+    base_image: str = "artifactapi.k8s.syd1.au.unkin.net/docker-internal/rpmbuilder:0.1.0-alma9"
     arch: str = 'amd64'
 
     def __str__(self):