[macos-runner] Replace actions/checkout@v4 with a plain git clone step

actions/checkout@v4 is a JS action, and act_runner's host-executor JS
action path hits a known upstream caching bug on this runner (nested
hostexecutor/.cache/act path never gets the downloaded action, causing
MODULE_NOT_FOUND on every run). Introducing a config.yaml to work around
it (workdir_parent) triggers a separate act_runner bug requiring a Docker
socket that doesn't exist on this Mac. Side-stepping both by doing the
checkout as a plain shell git clone, which the host executor runs fine.

.gitea/workflows/beta.yml

@@ -23,7 +23,11 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        run: |
+          REPO_URL="${{ gitea.server_url }}/${{ gitea.repository }}.git"
+          AUTH_URL="$(echo "$REPO_URL" | sed "s#https://#https://x-access-token:${{ gitea.token }}@#")"
+          git clone "$AUTH_URL" .
+          git checkout "${{ gitea.sha }}"
 
       - name: Set build number
         run: |

.gitea/workflows/release.yml

@@ -23,7 +23,11 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        run: |
+          REPO_URL="${{ gitea.server_url }}/${{ gitea.repository }}.git"
+          AUTH_URL="$(echo "$REPO_URL" | sed "s#https://#https://x-access-token:${{ gitea.token }}@#")"
+          git clone "$AUTH_URL" .
+          git checkout "${{ gitea.sha }}"
 
       - name: Verify ASC secrets
         run: |

.gitea/workflows/test.yml

@@ -18,7 +18,11 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        run: |
+          REPO_URL="${{ gitea.server_url }}/${{ gitea.repository }}.git"
+          AUTH_URL="$(echo "$REPO_URL" | sed "s#https://#https://x-access-token:${{ gitea.token }}@#")"
+          git clone "$AUTH_URL" .
+          git checkout "${{ gitea.sha }}"
 
       - name: Run unit tests
         run: |