feat: bump bpftrace version to v0.19.1

[cakemanny]

This resolves #200

It bumps the bptrace version to v0.19.1 .

I chose 0.19.1 as it's the most recent quay.io/iovisor/bpftrace tag. (It seems they are working on switching to using a Nix based build for later versions).
I wasn't able to successfully able to bump bcc.

The other changes are related to

• getting the Github Actions to run in the forked repo - i.e. $GIT_ORG is expanded in integration tests
• getting the integration tests to pass with more recent versions of Minikube and Kind.
  • I ended up bumping the version of go in order to be able to debug locally, so I hope it's ok that that's included also.

By all means let me know if it needs additional touches or splitting out into separate PRs.

[cakemanny]

It seems the github actions are actually failing still, I'll have to come back to this. I've put in draft mode for now.
I also tried to follow the instructions for signing the commits but for some reason they're showing as unverified so I'll have to revisit that too.

Now fixed. I'd simply gone a bit too far with the go builder base image; switching from bookworm back to bullseye sorted that. I also added something to output pod log contents when a test case fails.

[cakemanny]

@fntlnz, would you be the one to look at this?