chore(ci): remove old releases from forgejo-integration

The releases are created when:

* a tag is pushed to the integration repository it will create a
  vX.Y.Z release
* a new commit is pushed to a branch and mirrored to the integration
  repository, it will create a vX.Y-test release named after the branch

When both vX.Y.Z and vX.Y-test release are present, the end-to-end
tests will use vX.Y.Z because it comes first in release sort
order. This ensures that a last round of end-to-end tests is run from
the release built in the integration repository, exactly as it will be
published and signed.

In between stable releases, the vX.Y-test releases are built daily and
must be used instead for end-to-end testing so that problems can be
detected as soon as possible. For that to happen, the stable release
must be removed from the integration repository and this is done 24h
after they were published.

The vX.Y-test releases are removed if they have not been updated in 18
months. As of August 2024 it is possible for a LTS to still be needed
in tests over a year after it was last updated, although it is
unlikely that such a lack of activity happens, there is no reason to
remove the test release before that.

.forgejo/workflows/forgejo-integration-cleanup.yml

@@ -0,0 +1,40 @@
+on:
+  workflow_dispatch:
+
+  schedule:
+    - cron: '@daily'
+
+jobs:
+  integration-cleanup:
+    if: vars.ROLE == 'forgejo-integration'
+    runs-on: docker
+    container:
+      image: 'code.forgejo.org/oci/node:20-bookworm'
+    steps:
+
+      - name: apt install curl jq
+        run: |
+          export DEBIAN_FRONTEND=noninteractive
+          apt-get update -qq
+          apt-get -q install -qq -y curl jq
+
+      - name: remove old releases and tags
+        run: |
+          url=https://any:${{ secrets.TOKEN }}@codeberg.org
+          curl -sS "$url/api/v1/repos/forgejo-integration/forgejo/releases" | jq -r '.[] | "\(.published_at) \(.tag_name)"' | sort  | while read published_at version ; do
+            if echo $version | grep -e '-test$' >/dev/null; then
+              old="18 months"
+            else
+              old="1 day"
+            fi
+            too_old=$(env -i date --date="- $old" +%F)
+            too_old_seconds=$(env -i date --date="- $old" +%s)
+            published_at_seconds=$(env -i date --date="$published_at" +%s)
+            if test $published_at_seconds -le $too_old_seconds ; then
+              echo "$version was published more than $old ago ($published_at <= $too_old) and will be removed"
+              curl -X DELETE -sS "$url/api/v1/repos/forgejo-integration/forgejo/releases/tags/$version"
+              curl -X DELETE -sS "$url/api/v1/repos/forgejo-integration/forgejo/tags/$version"
+            else
+              echo "$version was published less than $old ago"
+            fi
+          done