[Flight SQL] Derby dependency (test scope) flagged as vulnerable to CVE-2022-46337 with no available Maven patch

### Describe the bug, including details regarding any error messages, version, and platform.

`flight-sql` uses `org.apache.derby:derby:10.15.2.0` in test scope, which is flagged
as vulnerable to [CVE-2022-46337](https://nvd.nist.gov/vuln/detail/CVE-2022-46337): a **critical (CVSS 9.8)** LDAP authentication bypass.

There is no fix available for this dependency and there never will be.

The NVD advisory lists `10.15.2.1` as the fix for the Java 11 branch, but that
version was never published to Maven Central. The same is true for `10.14.3.0` and
`10.16.1.2`. The only fixed release that exists on Maven Central is `10.17.1.0`
(Java 21+), which was also the last release ever made.

On 2025-10-10, the Derby PMC voted to retire the project into a read-only state.
Development and bug-fixing have ended and no further releases will be published. This
means the 10.15.x branch will remain vulnerable indefinitely with no upstream
resolution path.

Context on why the patch versions were never released:
- [DERBY-7147](https://issues.apache.org/jira/browse/DERBY-7147) — fix committed to branches, but no releases were cut for 10.14/10.15/10.16
- [DERBY-7178](https://issues.apache.org/jira/browse/DERBY-7178) — closed as "Not A Problem" by the Derby team

Since Derby is test scope only in `flight-sql`, there is no runtime exposure.
However, this causes persistent scanner noise for downstream consumers and the
situation will not improve on its own.

#### Possible paths forward:
- Upgrade to `10.17.1.0` (requires Java 21 as test baseline for `flight-sql`)
- Replace Derby with another embedded DB (e.g. H2) in `flight-sql` tests — likely
the cleanest long-term option given Derby's retirement

まず、flight-sql モジュール内の Derby の Maven 依存関係宣言を見つけ、それを使用しているテストを確認します。Derby をアップグレードする場合と別の組み込みデータベースに置き換える場合の Java-baseline への影響を比較します。完了の条件は、flight-sql のテストがパスし、脆弱な依存関係が報告されなくなることです。

索引モデルが issue の本文から書いたものです。