fix: replace actions/checkout with git clone to avoid SSL cert errors

The Forgejo runner's container images lack CA certificates, causing
actions/checkout@v4 to fail on SSL verification. Use direct git clone
(same approach as the test job) for release and docker jobs.

.forgejo/workflows/release.yml

@@ -54,12 +54,11 @@ jobs:
       new_version: ${{ steps.version.outputs.new_version }}
       skip: ${{ steps.version.outputs.skip }}
     steps:
-      - name: Install dependencies
+      - name: Install dependencies and checkout
-        run: apt-get update && apt-get install -y --no-install-recommends bash git python3
+        run: |
-
+          apt-get update && apt-get install -y --no-install-recommends bash git python3
-      - uses: actions/checkout@v4
+          git clone ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY}.git .
-        with:
+          git checkout ${GITHUB_SHA}
-          fetch-depth: 0
 
       - name: Determine version bump
         id: version
@@ -182,7 +181,10 @@ jobs:
       image: catthehacker/ubuntu:act-latest
       options: --privileged
     steps:
-      - uses: actions/checkout@v4
+      - name: Checkout repository
+        run: |
+          git clone --depth=1 ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY}.git .
+          git checkout ${GITHUB_SHA}
 
       - name: Build and push image
         shell: bash