v2.0.1 — TSan crash fix

Fix

• Pre-warm libxml2 encoding handlers on init — fixes a SEGV crash in xmlGetCharEncodingHandler when multiple threads call XMLEncoder.encode() concurrently. The global encoding handler table in libxml2 is lazily initialised and not thread-safe; we now resolve the UTF-8 handler during the single-threaded LibXML2.ensureInitialized() path.