fix(test): add robust retry logic for Windows temp directory cleanup

Windows file handle timing requires more aggressive retry strategy.
Multiple tests were still failing with EPERM errors during cleanup.

- Increase retries to 5 attempts with 50ms initial delay + 100ms between retries
- Only apply retry logic on Windows platform
- Allows up to 550ms total for file handles to be released
- Fixes remaining EPERM errors in json.test.ts on Windows CI

Author: jdalton

test/unit/json.test.ts

@@ -767,12 +767,23 @@ describe('json', () => {
 
     afterEach(async () => {
       if (testDir) {
-        // On Windows, add a small delay to ensure file handles are released
-        // before attempting to delete the temp directory
+        // On Windows, add retry logic for directory deletion due to file handle timing
         if (process.platform === 'win32') {
-          await sleep(100)
+          let retries = 5
+          while (retries > 0) {
+            try {
+              await sleep(50)
+              await safeDelete(testDir)
+              break
+            } catch (err) {
+              retries--
+              if (retries === 0) {throw err}
+              await sleep(100)
+            }
+          }
+        } else {
+          await safeDelete(testDir)
         }
-        await safeDelete(testDir)
       }
     })