x/website: update mentions of GOARCH=wasm files in misc/wasm to lib/wasm where needed

[dmitshur]

Now that issue #68024 is resolved, this issue tracks updating relevant documentation to reflect the Go 1.24 move of the .js and exec files to $(go env GOROOT)/lib/wasm (https://tip.golang.org/doc/go1.24#wasm).

There's already a few CLs that @Zxilly prepared:

• https://go.dev/cl/604119
• https://go.dev/cl/604916
• https://go.dev/cl/604835

CC @golang/js, @golang/wasm.

[dmitshur]

Added release-blocker for now so we can track this better. (It's a documentation only issue for a secondary port, so it wouldn't block the release in practice.)

[dmitshur]

All 3 CLs mentioned above are submitted, so I think this is done. Feel free to comment if we missed something.