Split functional testings via github action matrix

This commit changes the workflow of the github actions.

We split the workflow into different parts:

1) build zfs modules for Ubuntu 20.04 and 22.04 (~25m)
2) 2x zloop test (~10m) + 2x sanity test (~25m)
3) functional testings in parts 1..5 (each ~1h)
   - these could be triggered, when sanity tests are ok
   - currently I just start them all in the same time
4) cleanup and create summary

When everything is fine, the full run with all testings
should be done in around 2 hours.

The codeql.yml and checkstyle.yml are not part in this circle.

The testings are also modified a bit:
- report info about CPU and checksum benchmarks
- reset the debugging logs for each test
  - when some error occurred, we call dmesg with -c to get
    only the log output for the last failed test
  - we empty also the dbgsys

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tino Reichardt <milky-zfs@mcmilk.de>
Closes #14078

.github/workflows/zfs-linux.yml

@@ -0,0 +1,71 @@
+name: zfs-linux
+
+on:
+  push:
+  pull_request:
+
+jobs:
+
+  build:
+    name: Build
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [20.04, 22.04]
+    runs-on: ubuntu-${{ matrix.os }}
+    steps:
+    - uses: actions/checkout@v3
+      with:
+        ref: ${{ github.event.pull_request.head.sha }}
+    - name: Build modules
+      run: .github/workflows/scripts/setup-dependencies.sh build
+    - name: Prepare modules upload
+      run: tar czf modules-${{ matrix.os }}.tgz *.deb .github scripts/zfs-tests-color.sh tests/test-runner tests/ImageOS.txt
+    - uses: actions/upload-artifact@v3
+      with:
+        name: modules-${{ matrix.os }}
+        path: modules-${{ matrix.os }}.tgz
+    - name: Prepare scripts upload
+      run: tar czf scripts.tgz .github tests/test-runner
+    - uses: actions/upload-artifact@v3
+      with:
+        name: scripts
+        path: scripts.tgz
+
+  testings:
+    name: Testing
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [20.04, 22.04]
+    needs: build
+    uses: ./.github/workflows/zfs-linux-tests.yml
+    with:
+      os: ${{ matrix.os }}
+
+  cleanup:
+    if: always()
+    name: Cleanup
+    runs-on: ubuntu-22.04
+    needs: testings
+    steps:
+    - uses: actions/download-artifact@v3
+    - name: Generating summary
+      run: |
+        tar xzf scripts/scripts.tgz .github tests
+        .github/workflows/scripts/generate-summary.sh
+    # up to 4 steps, each can have 1 MiB output (for debugging log files)
+    - run: .github/workflows/scripts/generate-summary.sh 1
+    - run: .github/workflows/scripts/generate-summary.sh 2
+    - run: .github/workflows/scripts/generate-summary.sh 3
+    - run: .github/workflows/scripts/generate-summary.sh 4
+    - uses: actions/upload-artifact@v3
+      with:
+        name: Summary Files
+        path: Summary/
+    - uses: geekyeggo/delete-artifact@v2
+      with:
+        name: modules-20.04
+    - uses: geekyeggo/delete-artifact@v2
+      with:
+        name: modules-22.04