CI: Exempt rolling distro containers from zizmor image pinning

The package install tests deliberately run against the current Fedora
and Arch Linux container images, so ignore the unpinned-images audit at
each of those sites rather than pinning digests.

Author: terryburton

.github/workflows/package-install-tests.yml

@@ -148,7 +148,7 @@ jobs:
 
   build-rpm:
     runs-on: ubuntu-24.04
-    container: fedora:latest
+    container: fedora:latest # zizmor: ignore[unpinned-images]
 
     steps:
       - uses: actions/checkout@v6
@@ -189,7 +189,7 @@ jobs:
   test-rpm:
     needs: [upload-tests, build-rpm]
     runs-on: ubuntu-24.04
-    container: fedora:latest
+    container: fedora:latest # zizmor: ignore[unpinned-images]
 
     steps:
       - name: Download test scripts
@@ -233,7 +233,7 @@ jobs:
 
   build-arch:
     runs-on: ubuntu-24.04
-    container: archlinux:latest
+    container: archlinux:latest # zizmor: ignore[unpinned-images]
 
     steps:
       - uses: actions/checkout@v6
@@ -276,7 +276,7 @@ jobs:
   test-arch:
     needs: [upload-tests, build-arch]
     runs-on: ubuntu-24.04
-    container: archlinux:latest
+    container: archlinux:latest # zizmor: ignore[unpinned-images]
 
     steps:
       - name: Download test scripts