feat(ci): add benchci for better visualization (#149)

This adds a small in-repo tool and updates the ci.yml file in order
to make benchmark and most importantly allocation results visible in a
PR. It also drops the 3rdparty action we had commented out.

Signed-off-by: Marvin Drees <marvin.drees@9elements.com>

.github/workflows/ci.yaml

@@ -104,7 +104,7 @@ jobs:
     needs: [test]
     runs-on: ubuntu-latest
     permissions:
-      pull-requests: write
+      contents: read
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
@@ -115,20 +115,20 @@ jobs:
       - name: Run benchmarks
         run: go test -bench=. -benchmem -count=5 -shuffle=on -run='^$' -timeout=15m ./... | tee bench-results.txt
 
-      # Fails for a weird reason, will be investigated in the future
-      # - name: Report benchmark regressions
-      #   uses: benchmark-action/github-action-benchmark@a887eba2af2000fda74e733fcf952aa823b65916 # v1.21.0
-      #   with:
-      #     tool: go
-      #     output-file-path: bench-results.txt
-      #     summary-always: true
-      #     comment-on-alert: true
-      #     alert-threshold: "120%"
-      #     fail-on-alert: false
-      #     auto-push: ${{ github.event_name == 'push' && github.ref == 'refs/heads/main' }}
-      #     github-token: ${{ secrets.GITHUB_TOKEN }}
+      - name: Generate benchmark report
+        run: |
+          go run ./internal/benchci -current bench-results.txt -out bench-report.md
+          cat bench-report.md >> "$GITHUB_STEP_SUMMARY"
 
-      - name: Upload benchmark results
+      - name: Upload generated benchmark report
+        if: github.event_name == 'pull_request'
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          name: bench-report
+          path: bench-report.md
+          retention-days: 30
+
+      - name: Upload raw benchmark results
         if: always()
         uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
         with: