Replace script_plugins with a clippy like rustc driver (named crown) (#30508)

* Remove script_plugins

* Use crown instead of script_plugins

* crown_is_not_used

* Use crown in command base

* bootstrap crown

* tidy happy

* disable sccache

* Bring crown in tree

* Install crown from tree

* fix windows ci

* fix warning

* fix mac

libscript_plugins.dylib is not available anymore

* Update components/script/lib.rs

Co-authored-by: Martin Robinson <mrobinson@igalia.com>

* Update for nightly-2023-03-18

Mostly just based off https://github.com/servo/servo/pull/30630

* Always install crown

it's slow only when there is new version

* Run crown test with `mach test-unit`

* Small fixups; better trace_in_no_trace tests

* Better doc

* crown in config.toml

* Fix tidy for real

* no sccache on rustc_wrapper

* document rustc overrides

* fixup of compiletest

* Make a few minor comment adjustments

* Fix a typo in python/servo/platform/base.py

Co-authored-by: Samson <16504129+sagudev@users.noreply.github.com>

* Proper test types

* Ignore tidy on crown/tests

---------

Co-authored-by: Martin Robinson <mrobinson@igalia.com>

rust-toolchain.toml

@@ -1,11 +1,13 @@
 [toolchain]
 channel = "nightly-2023-03-18"
 components = [
-    # https://github.com/rust-lang/rust/issues/72594#issuecomment-633779564
+    # For support/crown
     "llvm-tools",
-    # For components/script_plugins, https://github.com/rust-lang/rust/pull/67469
+    # For support/crown
     "rustc-dev",
+    # For docs building
     "rust-docs",
+    # For formatting
     "rustfmt",
 ]
 profile = "minimal"