Upgrade to Node.js 24 (#103)

## Summary
This PR upgrades the GitHub Action to use Node.js 24 runtime and updates
all related dependencies.

## Changes
- ✅ Update `action.yml` to use `node24` runtime
- ✅ Update `@types/node` to latest version (24.5.2) for Node.js 24
support
- ✅ Update test matrix to remove deprecated Node.js versions (8, 10, 12,
14, 16)
- ✅ Keep testing against supported versions: 18, 20, 22, 24
- ✅ Bump major version to 2.0.0 (breaking change due to runtime upgrade)
- ✅ All dependencies verified compatible with Node.js 24

## Testing
- ✅ TypeScript build passes
- ✅ All tests pass
- ✅ No linting errors

## Breaking Changes
This is a major version bump (2.0.0) due to the runtime change from
Node.js 20 to Node.js 24. Users should test their workflows before
upgrading.

## Related
- Addresses GitHub's deprecation of Node.js 20 on Actions runners
- Aligns with GitHub's transition to Node.js 24 by March 2026

Author: ahanoff

.github/workflows/test.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node: [8, 10, 12, 14, 16, 18, 20, 22]
+        node: [18, 20, 22, 24]
     steps:
       - uses: actions/checkout@v4
 

action.yml

@@ -9,7 +9,7 @@ inputs:
     required: true
     description: MS Teams webhook URI
 runs:
-  using: node20
+  using: node24
   main: dist/main/index.js
 branding:
   icon: truck