x/website: generics and fuzzing tutorials have an outdated paragraph for Go 1.18 Beta

[gazerro]

The tutorial on generics has an outdated paragraph "Installing and using the beta"

https://go.dev/doc/tutorial/generics#installing_beta

Now that go 1.18 has been released, it should be removed.

[ianlancetaylor]

CC @eliben

[eliben]

Thanks for the report, @gazerro - we can get it fixed.

[gazerro]

The fuzzing tutorial also contains the paragraph "Installing and using the beta"

https://go.dev/doc/tutorial/fuzz

[dmitshur]

Thanks @eliben. I'll point out that CL 382057 makes a change related to this (and it can be closed after this issue is resolved).

[gopherbot]

Change https://go.dev/cl/393215 mentions this issue: _content/doc: change generics and fuzz tutorials from beta