delete the GitHub-hosted workflows

publish.yml computed and pushed a version tag on ubuntu-latest; the two
sync-*-branches jobs auto-merged dev into staging, polygon and vpn on
ubuntu-latest, a branch model that came with the fork and that this repo does
not use. The image build is untouched — docker.yml on lux-build and
release-matrix.yml on the luxfi-* pools both stay.

.github/workflows/publish.yml

@@ -1,31 +0,0 @@
-name: Docker
-on:
-  push:
-    branches:
-    - main
-    tags:
-    - v*
-  workflow_dispatch: null
-permissions:
-  contents: write
-  packages: write
-jobs:
-  version:
-    runs-on: ubuntu-latest
-    outputs:
-      version: ${{ steps.bump.outputs.version }}
-    steps:
-    - uses: actions/checkout@v4
-      with:
-        fetch-depth: 0
-        persist-credentials: true
-    - name: "Compute + tag version (v1.x.x \u2014 no major bumps)"
-      id: bump
-      run: "set -e\nif [[ \"${GITHUB_REF}\" == refs/tags/v* ]]; then\n  VERSION=\"${GITHUB_REF#refs/tags/v}\"\nelse\n  LAST=$(git\
-        \ tag -l 'v1.*' --sort=-v:refname | head -1)\n  if [ -z \"$LAST\" ]; then\n    NEW=\"1.0.0\"\n  else\n    MINOR=$(echo\
-        \ \"${LAST#v1.}\" | cut -d. -f1)\n    PATCH=$(echo \"${LAST#v1.}\" | cut -d. -f2)\n    MSG=$(git log -1 --pretty=%s)\n\
-        \    # feat: or BREAKING \u2192 minor bump, else \u2192 patch bump\n    # NO MAJOR BUMPS \u2014 capped at v1.x.x\n\
-        \    if [[ \"$MSG\" =~ ^(feat|BREAKING|[a-z]+!) ]]; then\n      NEW=\"1.$((MINOR+1)).0\"\n    else\n      NEW=\"1.$MINOR.$((PATCH+1))\"\
-        \n    fi\n  fi\n  VERSION=\"$NEW\"\n  git config user.name 'github-actions[bot]'\n  git config user.email 'github-actions[bot]@users.noreply.github.com'\n\
-        \  git tag \"v$VERSION\" || true\n  git push origin \"v$VERSION\" || echo \"tag push skipped\"\nfi\necho \"version=$VERSION\"\
-        \ >> \"$GITHUB_OUTPUT\"\necho \"VERSION=$VERSION\"\n"