Merge pull request cloudflare#2407 from cloudflare/mar/EW-8494-flag

Add KV Direct Binding compatibility flag.

[nfc] Update V8 => 12.6.228.9, clean up JSG V8 platform wrappers and …

…includes

As of this V8 version, TaskWrapper and the corresponding V8 patch are no
longer needed. Also drops a number of overrides in WorkerdPlatform and
V8PlatformWrapper where the base class function performs identical work.

Update rules_rust, further rust cleanup

Merge pull request cloudflare#340 from cloudflare/jsnell/nodejs-compa…

…t-buffer

Generate multiple types, one for each compatibility date that changes…

… type signatures (cloudflare#137)