Rollup merge of #82798 - jyn514:rustdoc-group, r=Manishearth,GuillaumeGomez

Rename `rustdoc` to `rustdoc::all`

When rustdoc lints were changed to be tool lints, the `rustdoc` group was removed, leading to spurious warnings like

```
warning: unknown lint: `rustdoc`
```

The lint group still worked when rustdoc ran, since rustdoc added the group itself.

This renames the group to `rustdoc::all` for consistency with `clippy::all` and the rest of the rustdoc lints.

Follow-up to #80527.
r? ``@Manishearth``

compiler/rustc_lint/src/lib.rs

@@ -346,6 +346,7 @@ fn register_builtins(store: &mut LintStore, no_interleave_lints: bool) {
         "intra_doc_link_resolution_failure",
         "use `rustdoc::broken_intra_doc_links` instead",
     );
+    store.register_removed("rustdoc", "use `rustdoc::all` instead");
 
     store.register_removed("unknown_features", "replaced by an error");
     store.register_removed("unsigned_negation", "replaced by negate_unsigned feature gate");