fixup! Mirror master and main

The workflow needs to be adjusted so that the just-pushed branch is
cloned (otherwise it is always the default branch that is cloned, even
if in the case that branch is stale).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

.github/workflows/mirror-master-and-main.yml

@@ -10,7 +10,9 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Partial clone
-        run: git clone --bare --depth=100 --single-branch --filter=blob:none ${{ github.event.repository.html_url }} .
+        env:
+          ref: ${{ github.event.ref }}
+        run: git clone --bare --depth=100 --single-branch --branch ${ref#refs/heads/} --filter=blob:none ${{ github.event.repository.html_url }} .
       - name: Push
         run: |
           git config http.https://github.com/.extraheader "Authorization: Basic $(echo -n x-access-token:${{ github.token }} | base64 --wrap=0)"