Fix CI: replace rollup-plugin-typescript2, downgrade TypeScript to 5.x

[Copilot]

TypeScript 7 gutted its CJS public API — it now only exports version and versionMajorMinor, dropping ModuleKind, createDocumentRegistry, and other APIs that rollup TypeScript plugins depend on. This caused the rollup -c build to fail with TypeError: tsModule.createDocumentRegistry is not a function across all CI jobs.

Changes (src/microsoft-trydotnet)

• Replaced rollup-plugin-typescript2 with @rollup/plugin-typescript — the actively maintained official Rollup plugin
• Downgraded typescript from ^7.0.2 → ^5.8.3 — latest stable TypeScript 5.x, compatible with all current rollup tooling
• Updated rollup.config.mjs to use @rollup/plugin-typescript's API (compilerOptions directly, no tsconfigOverride wrapper):

-import typescript from 'rollup-plugin-typescript2';
-import ts from 'typescript';
+import typescript from '@rollup/plugin-typescript';

 plugins: [
     typescript({
-        typescript: ts,
-        tsconfigOverride: { compilerOptions: { "module": "ES2015" } },
+        compilerOptions: { "module": "ES2015" },
     }),