no docker specification + no buster

.forgejo/workflows/forgejo-deb.yml

@@ -1,7 +1,7 @@
 on: [push, pull_request]
 jobs:
   build-forgejo-deb:
-    runs-on: docker://bookworm
+    runs-on: bookworm
     steps:
       - uses: actions/checkout@v4
         with:
@@ -79,7 +79,7 @@ jobs:
             repo-deb/*.deb
 
   installtest-bookworm-sqlite:
-    runs-on: docker://bookworm
+    runs-on: bookworm
     steps:
       - uses: actions/checkout@v4
 
@@ -94,7 +94,7 @@ jobs:
       - run: ./.ci-make.sh install-run-test ./forgejo-sqlite_*_arm64.deb
 
   installtest-bookworm-user:
-    runs-on: docker://bookworm
+    runs-on: bookworm
     steps:
       - uses: actions/checkout@v4
 
@@ -110,7 +110,7 @@ jobs:
       - run: ./.ci-make.sh install-run-test ./forgejo_*_arm64.deb
 
   testsuite-repo-upgrade-sqlite:
-    runs-on: docker://bookworm
+    runs-on: bookworm
     steps:
       - uses: actions/checkout@v4
 
@@ -127,23 +127,8 @@ jobs:
       - run: ./.ci-make.sh install-run-test ./forgejo-sqlite_*_arm64.deb
       - run: ./.ci-make.sh verify-data-dir-chmod
 
-  installtest-buster-bin:
-    runs-on: docker://buster
-    steps:
-      - uses: actions/checkout@v4
-
-      - name: "actions prep: installtest"
-        id: ciprep
-        run: ./.ci-make.sh actions-prep installtest
-
-      - uses: actions/download-artifact@v3
-        with:
-          name: forgejo-deb-${{ steps.ciprep.outputs.artifactlabel }}
-
-      - run: ./.ci-make.sh install-run-test ./forgejo-bin_*_arm64.deb
-
   publish-release-repo:
-    runs-on: docker://bookworm
+    runs-on: bookworm
     if: github.event_name == 'push' && contains(github.ref, 'refs/tags/')
     steps:
       - uses: actions/checkout@v4