github-ci: rename alma to almalinux; 8.4 to 8

.github/workflows/builds.yml

@@ -252,10 +252,10 @@ jobs:
 
   # This build also creates the distribution package that some other builds
   # depend on.
-  alma-8:
+  almalinux-8:
     name: AlmaLinux 8
     runs-on: ubuntu-latest
-    container: almalinux:8.4
+    container: almalinux:8
     needs: [prepare-deps, prepare-cbindgen]
     steps:
       # Cache Rust stuff.
@@ -387,7 +387,7 @@ jobs:
     name: CentOS 7
     runs-on: ubuntu-latest
     container: centos:7
-    needs: [prepare-deps, alma-8]
+    needs: [prepare-deps, almalinux-8]
     steps:
       - name: Cache ~/.cargo
         uses: actions/cache@9b0c1fce7a93df8e3bb8926b0d6e9d89e92f20a7
@@ -1210,7 +1210,7 @@ jobs:
     name: Ubuntu 20.04 (unsupported rust)
     runs-on: ubuntu-latest
     container: ubuntu:20.04
-    needs: alma-8
+    needs: almalinux-8
     steps:
       - name: Cache ~/.cargo
         uses: actions/cache@9b0c1fce7a93df8e3bb8926b0d6e9d89e92f20a7