sync-git-mailing-list-mirror: centralize the repository URLs

... and fix it up after moving the workflow to a different repository.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

.github/workflows/sync-git-mailing-list-mirror.yml

@@ -6,7 +6,9 @@ on:
     - cron:  "2,7,12,17,22,27,32,37,42,47,52,57 * * * *"
 
 env:
-  LORE_EPOCH: 1
+  LORE_EPOCH: 1 # also adjust SOURCE_REPOSITORY
+  SOURCE_REPOSITORY: https://lore.kernel.org/git/1 # LORE_EPOCH
+  TARGET_GITHUB_REPOSITORY: gitgitgadget/git-mailing-list-mirror
 
 concurrency:
   group: sync-git-mailing-list-mirror
@@ -20,12 +22,12 @@ jobs:
     steps:
     - name: Partial clone
       run: |
-        git clone --bare --depth=1 -b lore-$LORE_EPOCH --filter=blob:none https://github.com/$GITHUB_REPOSITORY .
+        git clone --bare --depth=1 -b lore-$LORE_EPOCH --filter=blob:none https://github.com/$TARGET_GITHUB_REPOSITORY .
     - name: Update from lore.kernel.org
       run: |
-        git fetch https://lore.kernel.org/git/$LORE_EPOCH refs/heads/master:refs/heads/lore-$LORE_EPOCH
+        git fetch "$SOURCE_REPOSITORY" refs/heads/master:refs/heads/lore-$LORE_EPOCH
     - name: Push to mirror
       env:
         GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
       run: |
-        git push https://$GITHUB_ACTOR:[email protected]/$GITHUB_REPOSITORY lore-$LORE_EPOCH
+        git push https://$GITHUB_ACTOR:[email protected]/$TARGET_GITHUB_REPOSITORY lore-$LORE_EPOCH