Bump version to 0.3.0 with pg16 compat

[olirice]

What kind of change does this PR introduce?

Adds pg16 compatibility in a formal release

[olirice]

@imor do you have any idea what's going on with that build failure? Its reproducible locally with

docker-compose -f .ci/docker-compose.yaml run test_pg_jsonschema

but is only occurring for me inside docker, not natively

[imor]

@imor do you have any idea what's going on with that build failure? Its reproducible locally with

docker-compose -f .ci/docker-compose.yaml run test_pg_jsonschema

but is only occurring for me inside docker, not natively

Fixed by using stable toolchain instead of nightly. The ahash crate had made some incorrect assumptions which were broken in a recent nightly release. This was fixed in ahash 0.8.7 but pgrx 0.11.2 still depended on an older affected version (0.8.3).

ahash ticket:

tkaitchuck/aHash#200