Can the GraalVM Presubmit checks be faster?

[diegomarquezp]

These checks take usually ~35 minutes. I wonder if we can make them faster somehow.

[mpeddada1]

Adding some observations on times to understand where the delays are coming from:

From #2581

Building sdk-platform-java dependencies: 02:02 min
Showcase
Run showcase tests: 2 mins
Generate native image: 11 min
Run tests after native image build: 1 min

Monorepo - KMS
Run tests for KMS: 1 min
Generate native image: 10 mins
Run tests after native image build: <1 min

Monorepo - KMS Inventory
Run tests for KMS Inventory: <1 min
Generate native image: 10 min
Run tests after native image build: <1 min

Building the native images appears to be taking a majority of time.

One idea: The graalvm script first runs the showcase job and then the monorepo tests sequentially. There may be an opportunity for us to parallelize this.