[workflows] Remove fix-version-gaps (#190721)

This workflow was intended to automatically update labels if a pull
requests version targets were out of date at the time of merge (i.e. a a
pull request labeled with 8.14 as a target branch, is now out of date
after the global version is bumped to 8.16, will add the 8.15 label)

We don't add target versions anymore pre-merge except in rare cases like
documentation updates. This last time this workflow was run was 2.5
years ago.

.github/workflows/fix-version-gaps.yml

@@ -1,42 +0,0 @@
-on:
-  pull_request:
-    branches:
-      - main
-    types:
-      - closed
-
-jobs:
-  gaps:
-    name: Fix Version Label Gaps
-    # This fix also runs as part of the backport action (because backport depends on the labels)
-    # So we only need to trigger it for merged PRs that also won't be auto-backported
-    if: |
-      github.event.pull_request.merged == true
-      && !contains(github.event.pull_request.labels.*.name, 'auto-backport')
-      && !(
-        contains(github.event.pull_request.labels.*.name, 'backport:prev-minor')
-        || contains(github.event.pull_request.labels.*.name, 'backport:prev-major')
-        || contains(github.event.pull_request.labels.*.name, 'backport:current-major')
-        || contains(github.event.pull_request.labels.*.name, 'backport:all-open')
-        || contains(github.event.pull_request.labels.*.name, 'backport:version')
-      )
-      && !(
-        (github.event.action == 'labeled' && github.event.label.name == 'auto-backport')
-        || (github.event.action == 'closed')
-      )
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout Actions
-        uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
-        with:
-          repository: 'elastic/kibana-github-actions'
-          ref: main
-          path: ./actions
-
-      - name: Install Actions
-        run: npm ci --omit=dev --prefix ./actions
-
-      - name: Run Fix Gaps
-        uses: ./actions/fix-version-gaps
-        with:
-          github_token: ${{secrets.KIBANAMACHINE_TOKEN}}