[SPARK-53698] Support Swift 6.2

### What changes were proposed in this pull request?

This PR aims to support `Swift 6.2` by adding the official test coverage and updating `README.md`.

### Why are the changes needed?

`Swift 6.2` is released on 2025-09-15 finally. We need to support it officially.

- https://www.swift.org/blog/swift-6.2-released/

### Does this PR introduce _any_ user-facing change?

No behavior change.

### How was this patch tested?

Pass the CIs.

### Was this patch authored or co-authored using generative AI tooling?

No.

Closes #243 from dongjoon-hyun/SPARK-53698.

Authored-by: Dongjoon Hyun <[email protected]>
Signed-off-by: Dongjoon Hyun <[email protected]>

Author: dongjoon-hyun

.github/workflows/build_and_test.yml

@@ -90,8 +90,8 @@ jobs:
     - uses: actions/checkout@v5
     - name: Build
       run: |
-        docker run swiftlang/swift:nightly-6.2-amazonlinux2 uname -a
-        docker run -v $PWD:/spark -w /spark swiftlang/swift:nightly-6.2-amazonlinux2 swift build
+        docker run swift:6.2 uname -a
+        docker run -v $PWD:/spark -w /spark swift:6.2 swift build -c release
 
   integration-test-ubuntu:
     runs-on: ubuntu-latest

README.md

@@ -17,7 +17,7 @@ So far, this library project is tracking the upstream changes of [Apache Arrow](
 ## Requirement
 
 - [Apache Spark 4.0.0 (May 2025)](https://github.com/apache/spark/releases/tag/v4.0.0)
-- [Swift 6.0 (2024) or 6.1 (2025)](https://swift.org)
+- [Swift 6.0/6.1/6.2 (September 2025)](https://swift.org)
 - [gRPC Swift 2.1 (July 2025)](https://github.com/grpc/grpc-swift-2/releases/tag/2.1.0)
 - [gRPC Swift Protobuf 2.1 (August 2025)](https://github.com/grpc/grpc-swift-protobuf/releases/tag/2.1.1)
 - [gRPC Swift NIO Transport 2.1 (August 2025)](https://github.com/grpc/grpc-swift-nio-transport/releases/tag/2.1.0)