Fix not displaying 405

[gewenyu99]

What does this PR do?

• Adds checks to see when a request is unimplemented, if the route is unimplemented, or just the method is unsupported.
• Returns 405 correctly
• related to Issue Bun server returns 404 when route exists but HTTP method is not handled #18197

• Documentation or TypeScript types (it's okay to leave the rest blank in this case)
• Code changes

How did you verify your code works?

• I checked the lifetime of memory allocated to verify it's (1) freed and (2) only freed when it should be
• I included a test for the new code, or an existing test covers it
• JSValue used outside outside of the stack is either wrapped in a JSC.Strong or is JSValueProtect'ed
• I wrote TypeScript/JavaScript tests and they pass locally (bun-debug test test-file-name.test)

[nektro]

The server must generate an Allow header in a 405 response with a list of methods that the target resource currently supports.

https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Status/405

[gewenyu99]

Also question about these builds. I'm seeing 6/6 passes and exit code 2, is there something im missing here?