Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Signed-off-by: Andrew Innes <andrew.c12@gmail.com>
Closes #15828 

GitHub Actions is transitioning from Node 16 to Node 20.

So we need to update these:
- actions/checkout@v3 -> v4
- actions/download-artifact@v3 -> v4
- actions/upload-artifact@v3 -> v4 and some minor changes

Update also the documentation of the testings workflow.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Andrew Innes <andrew.c12@gmail.com>
Signed-off-by: Tino Reichardt <milky-zfs@mcmilk.de>
Closes #15820 

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