Release Notes for v6.1.9

Fixes

• Backported V8 patch to fix bug in type inference. #22429
• Fixed an OOB access in ReadableStream::Close (https://crbug.com/1045931). #22436
• Fixed an integer overflow crash in ICU (https://crbug.com/1044570). #22422
• Fixed crash with seccomp-bpf sandbox on linux and glibc 2.31. #22339