ORC-2117: Add Java 26-ea to GitHub Action build job

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

This PR aims to add `Java 26-ea` to GitHub Action `build` job.

### Why are the changes needed?

This is a known issue of Java 25 which is tracked by ORC-2116.
- https://bugs.openjdk.org/browse/JDK-8377811 (Expected on April 2026 via Java 25.0.3)
- https://bugs.openjdk.org/browse/JDK-8370807 (Expected on March 17, 2026)

New Java 26 test coverage will help us.

### How was this patch tested?

Pass the CIs.

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

Generated-by: `Gemini 3.1 Pro (High)` on `Antigravity`

Closes #2565 from dongjoon-hyun/ORC-2117.

Authored-by: Dongjoon Hyun <dongjoon@apache.org>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>

Author: dongjoon-hyun

.github/workflows/build_and_test.yml

@@ -86,6 +86,9 @@ jobs:
           - os: ubuntu-24.04-arm
             java: 17
             cxx: clang++
+          - os: ubuntu-latest
+            java: 26-ea
+            cxx: clang++
     env:
       MAVEN_OPTS: -Xmx2g
       MAVEN_SKIP_RC: true