Revert "Introduce issuegenerator to open issues when tests fail on main (#38177)" (#38231)

This reverts commit b072b17.

When introducing the previous commit to main, we noticed the steps are
not well connected. For some reason that we're still investigating the
JUnit artifacts aren't uploaded and the last step that depends on them
always fail.

Author: ArthurSens

.github/workflows/build-and-test.yml

@@ -648,27 +648,3 @@ jobs:
                 return
               }
             }
-
-  flakytests-generate-issues:
-    if: github.event_name == 'push' && github.ref == 'refs/heads/main'
-    runs-on: ubuntu-24.04
-    needs: [unittest-matrix]
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/download-artifact@v4
-        with:
-          merge-multiple: true
-          pattern: test-results-*
-          path: ./internal/tools/testresults/
-      - name: Install Tools
-        run: make install-tools
-      - name: Generate Issues
-        run: |
-          # We want to start by generating issues of a single component
-          # As we mature the usage of issuegenerator, we can extend it to
-          # generate issues for multiple components.
-          #
-          # We'll start with the hostmetricsreceiver.
-          mkdir -p ./internal/tools/testresults/hostmetricsreceiver
-          mv ./internal/tools/testresults/github.colasdn.workers.dev-open-telemetry-opentelemetry-collector-contrib-receiver-hostmetricsreceiver-junit.xml ./internal/tools/testresults/hostmetricsreceiver/
-          ./tools/issuegenerator -path ./internal/tools/testresults/hostmetricsreceiver/