[KYUUBI #6142] Deprecate Flink 1.16

# 🔍 Description
## Issue References 🔗
This pull request add a message to tell users that Flink 1.16 is deprecated.

Disscusion: https://lists.apache.org/thread/fmq7462vcfm8l3m38xh4b4jjgd4smzn7

## Describe Your Solution 🔧
Add a message to tell users that Flink 1.16 is deprecated.

## Types of changes 🔖

- [ ] Bugfix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing functionality to change)

## Test Plan 🧪

#### Behavior Without This Pull Request ⚰️

#### Behavior With This Pull Request 🎉

#### Related Unit Tests

---

# Checklist 📝

- [x] This patch was not authored or co-authored using [Generative Tooling](https://www.apache.org/legal/generative-tooling.html)

**Be nice. Be informative.**

Closes #6142 from zhouyifan279/dep-flink-1.16.

Closes #6142

e38a4810c [Cheng Pan] nit
d03b106cf [zhouyifan279] Deprecate Flink 1.16

Lead-authored-by: zhouyifan279 <zhouyifan279@gmail.com>
Co-authored-by: Cheng Pan <chengpan@apache.org>
Signed-off-by: Cheng Pan <chengpan@apache.org>

docs/deployment/migration-guide.md

@@ -24,6 +24,7 @@
 * Since Kyuubi 1.9.0, the support of Spark SQL engine for Spark 3.1 is deprecated, and will be removed in the future.
 * Since Kyuubi 1.9.0, the support of Spark extensions for Spark 3.1 is removed, please use Spark 3.2 or higher versions.
 * Since Kyuubi 1.9.0, `kyuubi.frontend.login.timeout`, `kyuubi.frontend.thrift.login.timeout`, `kyuubi.frontend.backoff.slot.length`, `kyuubi.frontend.thrift.backoff.slot.length` are removed.
+* Since Kyuubi 1.9.0, the support of Flink engine for Flink 1.16 is deprecated, and will be removed in the future.
 
 ## Upgrading from Kyuubi 1.8.0 to 1.8.1
 

externals/kyuubi-flink-sql-engine/src/main/scala/org/apache/kyuubi/engine/flink/FlinkEngineUtils.scala

@@ -56,6 +56,9 @@ object FlinkEngineUtils extends Logging {
     val flinkVersion = EnvironmentInformation.getVersion
     if (SUPPORTED_FLINK_VERSIONS.contains(FLINK_RUNTIME_VERSION)) {
       info(s"The current Flink version is $flinkVersion")
+      if (FlinkEngineUtils.FLINK_RUNTIME_VERSION === "1.16") {
+        warn("The support for Flink 1.16 is deprecated, and will be removed in the next version.")
+      }
     } else {
       throw new UnsupportedOperationException(
         s"You are using unsupported Flink version $flinkVersion, " +