ci: upgrade Node.js from 18 to 22 across workflows (#1063)

## Summary

- Bumps `NODE_VERSION` from 18 to 22 in `test.yml`, `browserstack.yml`,
and `integration.yml`
- Node 18 reached end-of-life in April 2025 and is incompatible with the
current toolchain (TypeScript 5.8 / rollup-plugin-typescript2)
- Node 22 is the current Active LTS (EOL April 2027), consistent with
`release.yml` and the build action default

## Test plan

- [ ] CI passes on this PR

Author: yogeshchoudhary147

.github/workflows/browserstack.yml

@@ -19,7 +19,7 @@ concurrency:
   cancel-in-progress: ${{ github.ref != 'refs/heads/main' }}
 
 env:
-  NODE_VERSION: 18
+  NODE_VERSION: 22
 
 jobs:
 

.github/workflows/integration.yml

@@ -19,7 +19,7 @@ concurrency:
   cancel-in-progress: ${{ github.ref != 'refs/heads/main' }}
 
 env:
-  NODE_VERSION: 18
+  NODE_VERSION: 22
 
 jobs:
   test-examples:

.github/workflows/test.yml

@@ -18,7 +18,7 @@ concurrency:
   cancel-in-progress: ${{ github.ref != 'refs/heads/main' }}
 
 env:
-  NODE_VERSION: 18
+  NODE_VERSION: 22
   CACHE_KEY: '${{ github.ref }}-${{ github.run_id }}-${{ github.run_attempt }}'
 
 jobs: