Make generateParams e2e cleanup best-effort to fix Windows EPERM flake

[Copilot]

The Windows VSCode extension e2e job in #19786 failed with Tests: 38 passed, 39 total — the generateParams test body passed but its finally cleanup hit EPERM on rmSync because VS Code's file watcher still held main.parameters.json. Baselines in #19786 were regenerated correctly; this failure is unrelated to that PR.

Changes

• src/vscode-bicep/src/test/e2e/generateParams.test.ts: replace rmSync(tempFolder, { recursive: true, force: true }) with the same best-effort pattern already used by decompile.test.ts, emptyConfigFileSnippets.test.ts, and createBicepConfig.test.ts — maxRetries: 5, retryDelay: 1000, wrapped in try/catch so transient Windows file-handle races during cleanup don't fail an otherwise-passing test.

} finally {
  try {
    fs.rmSync(tempFolder, {
      recursive: true,
      maxRetries: 5,
      retryDelay: 1000,
    });
  } catch {
    // post-test cleanup is strictly best-effort only
  }
}

Relevant log excerpt:

[File Watcher (node.js)] Failed to watch ...\main.parameters.json ... EPERM
✘ generateParams should generate parameters file if the compiled template already exists
Error: EPERM, Permission denied: \\?\C:\Users\RUNNER~1\AppData\Local\Temp\bicep-generate-params-m5dWpY
    at rmSync (src/vscode-bicep/src/test/e2e/generateParams.test.ts:60:10)

Original prompt

check our local bicep branch for this pr we haveand to see why this test fails:
Test Suites: 12 passed, 13 total
Tests: 38 passed, 39 total
[main 2026-06-03T23:23:21.705Z] Extension host with pid 6844 exited with code: 1, signal: unknown.
Extension host test runner error { name: 'Canceled' }
Asking native host service to exit with code 1.
Exit code: 1
TestRunFailedError: Test run failed with code 1
at ChildProcess.onProcessClosed (D:\a\bicep\bicep\src\vscode-bicep\node_modules@vscode\test-electron\out\runTest.js:110:24)
at ChildProcess.emit (node:events:509:28)
at ChildProcess._handle.onexit (node:internal/child_process:295:12) {
code: 1,
signal: undefined
}
Error: Process completed with exit code 1.
##[debug]Finishing: Run E2E tests

did we update baselines? #19786

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