Part of #1641.

• Add: 3.8.0 (supported)
• Deprecate: 3.6.0
• Remove: 3.4.0

Update tasks

• Update boil-config.toml to reflect the agreed upon versions in the spreadsheet (including the removal of old versions).
• Update boil-config.toml to the latest supported version of JVM (base and devel).
• Update other dependencies if applicable (eg: security-plugin, etc).
• Check other operators (getting_started / kuttl / supported-versions) for usage of the versions. Add the PR(s) to the list below.
• Update the version in demos. Add the PR(s) to the list below.

Related Pull Requests

• chore(opensearch): Bump to 3.8.0 #1669
• chore(opensearch): Update major/minor versions for 26.11.0 opensearch-operator#189
• chore(opensearch): Update major/minor versions for 26.11.0 demos#456

Acceptance

• Can build image (either locally, or in CI)
• All kuttl tests pass (either locally, or in CI)
• Release notes written in a comment below
• Applicable release-note label added to this issue

# Where x.y.z is the new version added in this PR
boil build opensearch=x.y.z --strip-architecture --load

kind load docker-image oci.stackable.tech/sdp/opensearch:x.y.z-stackable0.0.0-dev

# Change directory into the opensearch-operator repository and update the
# product version in tests/test-definition.yaml
./scripts/run-tests --test-suite smoke-latest # or similar

Please consider updating this template if these instructions are wrong, or
could be made clearer.