Bump the version on main to 9.5.0

[elastic-vault-github-plugin-prod]

No description provided.

[pierrehilbert]

/test

[ebeahan]

/test

[ebeahan]

Do the E2E tests have any handling if there's a mismatch in the available Elasticsearch version? Seems like the reason for the E2E test CI failures:

{"log.level":"info","@timestamp":"2026-04-10T17:19:32.544Z","log.origin":{"function":"github.com/elastic/elastic-agent/internal/pkg/agent/cmd.waitForFleetServer.func1","file.name":"cmd/enroll_cmd.go","file.line":591},"message":"Fleet Server - Error - failed version compatibility check with elasticsearch (Agent: 9.5.0-SNAPSHOT, Elasticsearch: 9.4.0): unsupported version","ecs.version":"1.6.0"}

[ebeahan]

Will try CI again once a 9.5.0-SNAPSHOT is published for Elasticsearch into DRA.

[ebeahan]

/test

[ebeahan]

Remaining CI failure expected (see #6085 (comment) for more context).