Updates the managed `com.vaadin:license-checker` version to 2.3.3.

2.3.3 contains three offline key changes:

- Version-scoped maintenance tokens (`cm<major>`,
`v<major>extendedsupport`) are now matched against the Vaadin generation
a Flow version shipped in, instead of against the Flow major. A Vaadin
14 application reports Flow 2.x, so a key carrying `v14extendedsupport`
was rejected (vaadin/license-checker-vaadin10#256).
- A warning is logged when the offline or server license key in use
expires within 30 days, so the key can be renewed before builds start
failing (vaadin/license-checker-vaadin10#254).
- When an offline key does not grant access to a Flow version, the error
message now explains that the release is commercially maintained, names
the subscription needed and lists what the key in use actually covers.
Before, the message only stated that access was denied.

Validation also got stricter in one place: `v8extendedsupport` means
Vaadin Framework 8 and no longer grants Flow 8.x, and Flow 3.x-9.x
(Vaadin 16-22) accept no version-scoped token at all.

### Compatibility

2.3.2 -> 2.3.3 adds, removes and changes no public or protected API —
verified by comparing the released jars with `javap` — so it is a
drop-in replacement.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: totally-not-ai[bot] <290682512+totally-not-ai[bot]@users.noreply.github.com>
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>