CI: Make mandrel.yml trigger on workflow_dispatch

[zakkak]

This allows us to run the workflow on demand and on schedule with different parameters.

For the currently scheduled builds see nightly.yml

With gh (aka github CLI) we can also trigger tests from the command line like this:

# Use latest builder image of Mandrel 20.3 from quay,io and test with Quarkus main
gh workflow -R zakkak/mandrel run base.yml --ref ci-refactoring \
    -f quarkus-version=main -f builder-image=quay.io/quarkus/ubi-quarkus-mandrel:20.3-java11
# Download GraalVM CE 21.1.0 and test with Quarkus main
gh workflow -R zakkak/mandrel run base.yml --ref ci-refactoring \
    -f quarkus-version=main -f version=vm-21.1.0 -f distribution=graalvm -f build-from-source=false
# Download Mandrel 21.0.0.0-Final and test with Quarkus main
gh workflow -R zakkak/mandrel run base.yml --ref ci-refactoring \
    -f quarkus-version=main -f version=mandrel-21.0.0.0-Final -f build-from-source=false
# Default: build graal/master with mandrel-packaging and test with Quarkus main
gh workflow -R zakkak/mandrel run base.yml --ref ci-refactoring
# etc.

Relates to: quarkusio/quarkus#16631

[zakkak]

The failures are because base.yml does not exist in the repository yet. After merging it should be OK.

[Karm]

👍

[zakkak]

The failures are because base.yml does not exist in the repository yet. After merging it should be OK.

Hmm it looks like I was wrong https://github.com/graalvm/mandrel/actions/runs/772097210
At least now it will be easier for me to test the triggering API since https://github.com/graalvm/mandrel/actions/workflows/base.yml is in place :)