Auto merge of #9541 - Alexendoo:declare-proc-macro, r=flip1995

Generate lint categories and explanations with `declare_clippy_lint`

This means contributors will no longer have to run `cargo dev update_lints` after changing a lints documentation or its category, which may also mean fewer merge conflicts in general

It works by swapping `declare_clippy_lint` out for a `proc_macro` of the same name. The proc macro emits a `LintInfo` alongside the generated `Lint` which are gathered into `declared_lint::LINTS`. The categories/explanations are then read from `declared_lint::LINTS` at runtime

The removal of `src/docs` is split into a separate commit to be more easily ignored

It is slightly slower though, adding a bit under a second to build time. Less noticeable in full builds or with a slower linker (benchmark uses mold)

```bash
hyperfine --warmup 2 \
    --parameter-list commit "declare-proc-macro,master" \
    --command-name "{commit}" \
    --setup "git checkout {commit}" \
    --prepare "touch clippy_lints/src/lib.rs" \
    "cargo build"
```
```
Benchmark 1: declare-proc-macro
  Time (mean ± σ):     10.731 s ±  0.154 s    [User: 7.739 s, System: 1.791 s]
  Range (min … max):   10.598 s … 11.125 s    10 runs

Benchmark 2: master
  Time (mean ± σ):      9.422 s ±  0.094 s    [User: 7.183 s, System: 1.732 s]
  Range (min … max):    9.287 s …  9.624 s    10 runs

Summary
  'master' ran
    1.14 ± 0.02 times faster than 'declare-proc-macro'
```

r? `@flip1995`
cc `@llogiq` for `--explain`

changelog: none

1 files changed, 10 insertions, 5 deletions

diff --git a/tests/versioncheck.rs b/tests/versioncheck.rs
index a6d8d0307ce..7a85386a3df 100644
--- a/tests/versioncheck.rs
+++ b/tests/versioncheck.rs
@@ -6,7 +6,7 @@ use rustc_tools_util::VersionInfo;
 use std::fs;
 
 #[test]
-fn check_that_clippy_lints_and_clippy_utils_have_the_same_version_as_clippy() {
+fn consistent_clippy_crate_versions() {
     fn read_version(path: &str) -> String {
         let contents = fs::read_to_string(path).unwrap_or_else(|e| panic!("error reading `{path}`: {e:?}"));
         contents
@@ -24,11 +24,16 @@ fn check_that_clippy_lints_and_clippy_utils_have_the_same_version_as_clippy() {
     }
 
     let clippy_version = read_version("Cargo.toml");
-    let clippy_lints_version = read_version("clippy_lints/Cargo.toml");
-    let clippy_utils_version = read_version("clippy_utils/Cargo.toml");
 
-    assert_eq!(clippy_version, clippy_lints_version);
-    assert_eq!(clippy_version, clippy_utils_version);
+    let paths = [
+        "declare_clippy_lint/Cargo.toml",
+        "clippy_lints/Cargo.toml",
+        "clippy_utils/Cargo.toml",
+    ];
+
+    for path in paths {
+        assert_eq!(clippy_version, read_version(path), "{path} version differs");
+    }
 }
 
 #[test]