feat: release process

[amannocci]

What is the change being made?

• Implement full release process.

Why is the change being made?

• Add the ability to release a new version without lifting branch protections.

[v1v]

There will be another follow-up with the changes in

elastic-otel-java/.ci/release.sh

Lines 31 to 32 in 8fcbb73

	### TODO: changeme
	publishArg='assemble'

, won't it?

[v1v]

LGTM, thanks @amannocci for this! 💯

As I mentioned in a previous comment,

elastic-otel-java/.ci/release.sh

Lines 31 to 32 in 8fcbb73

	### TODO: changeme
	publishArg='assemble'

will need to be accommodated to run the release.

In a follow-up, so we play safe?

@SylvainJuge, what's the required target goal? The same as

elastic-otel-java/.ci/snapshot.sh

Line 31 in dc4c6ea

publishArg='publishToSonatype closeAndReleaseStagingRepository'

?

[SylvainJuge]

@SylvainJuge, what's the required target goal? The same as

elastic-otel-java/.ci/snapshot.sh

Line 31 in dc4c6ea

publishArg='publishToSonatype closeAndReleaseStagingRepository'

?

It's the same as the snapshot, so:

 publishArg='publishToSonatype closeAndReleaseStagingRepository'

When run with a non-snapshot version it should publish to the releases repository.

[amannocci]

@SylvainJuge, what's the required target goal? The same as

elastic-otel-java/.ci/snapshot.sh

Line 31 in dc4c6ea

publishArg='publishToSonatype closeAndReleaseStagingRepository'

?

It's the same as the snapshot, so:

 publishArg='publishToSonatype closeAndReleaseStagingRepository'

When run with a non-snapshot version it should publish to the releases repository.

Ref: e1864cd