chore: Adds SentryFileManager and SentrySerialization to dangerous files (#4307)

Author: kahest

.github/file-filters.yml

@@ -10,3 +10,6 @@ high_risk_code: &high_risk_code
   - 'Sources/Sentry/SentrySwizzleWrapper.m'
   - 'Sources/Sentry/include/SentrySwizzle.h'
   - 'Sources/Sentry/SentrySwizzle.m'
+  - 'Sources/Sentry/SentryFileManager.m'
+  - 'Sources/Sentry/SentrySerialization.m'
+  - 'Sources/Sentry/SentrySerialization.h'