Prepare version v0.30.0 (#1121)

Contains one small bug fix, but mainly exposes a new `rivershared`
package for common tag extraction logic (see #1120).

[skip ci]

release rivertype/v0.30.0

release rivershared/v0.30.0

release riverdriver/v0.30.0

release riverdriver/riversqlite/v0.30.0

release riverdriver/riverpgxv5/v0.30.0

release riverdriver/riverdatabasesql/v0.30.0

release cmd/river/v0.30.0

Prepare version 0.29.0 (#1110)

Prepare version 0.29.0. We pull the changes from RC1 into the main
0.29.0 release.

[skip ci]

release rivertype/v0.29.0