Added workflow for triggering the Codecov bot in PRs (#557)

Author: brownbaerchen

.github/workflows/trigger_coverage_bot.yml

@@ -0,0 +1,48 @@
+---
+
+name: Trigger coverage bot
+
+on:
+  workflow_run:
+    workflows: ["CI pipeline for pySDC"]
+    types: ["completed"]
+  
+jobs:
+
+  Upload to Codecov:
+    runs-on: ubuntu-latest
+
+    if: ${{ github.repository_owner == 'Parallel-in-Time' && github.event.workflow_run.conclusion == 'success' && github.event.workflow_run.pull_requests != '' }}
+
+    defaults:
+      run:
+        shell: bash -l {0}
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install Conda environment with Micromamba
+        uses: mamba-org/setup-micromamba@v1
+        with:
+          environment-file: "etc/environment-postprocess.yml"
+
+      - name: Downloading artifacts
+        uses: actions/download-artifact@v4
+        with:
+          path: .
+          merge-multiple: true
+          run-id: ${{ github.event.workflow_run.id }}
+          github-token: ${{ secrets.ACTION_READ_TOKEN }}
+
+      - name: Prepare artifacts
+        run: |
+          python -m coverage combine coverage_*.dat
+          python -m coverage xml
+          python -m coverage html
+
+      - name: Upload coverage reports to Codecov
+        uses: codecov/codecov-action@v4
+        with:
+          token: ${{ secrets.CODECOV }}
+