Rollup merge of #134006 - klensy:typos, r=nnethercote

setup typos check in CI

This allows to check typos in CI, currently for compiler only (to reduce commit size with fixes). With current setup, exclude list is quite short, so it worth trying?

Also includes commits with actual typo fixes.

MCP: https://github.com/rust-lang/compiler-team/issues/817

typos check currently turned for:
* ./compiler
* ./library
* ./src/bootstrap
* ./src/librustdoc

After merging, PRs which enables checks for other crates (tools) can be implemented too.

Found typos will **not break** other jobs immediately: (tests, building compiler for perf run). Job will be marked as red on completion in ~ 20 secs, so you will not forget to fix it whenever you want, before merging pr.

Check typos: `python x.py test tidy --extra-checks=spellcheck`
Apply typo fixes: `python x.py test tidy --extra-checks=spellcheck:fix` (in case if there only 1 suggestion of each typo)

Current fail in this pr is expected and shows how typo errors emitted. Commit with error will be removed after r+.

.github/workflows/spellcheck.yml

@@ -0,0 +1,23 @@
+# This workflow runs spellcheck job
+
+name: Spellcheck
+on:
+  pull_request:
+    branches:
+      - "**"
+
+jobs:
+  spellcheck:
+    name: run spellchecker
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout the source code
+        uses: actions/checkout@v4
+
+      - name: check typos
+        # sync version with src/tools/tidy/src/ext_tool_checks.rs in spellcheck_runner
+        uses: crate-ci/typos@v1.34.0
+        with:
+          # sync target files with src/tools/tidy/src/ext_tool_checks.rs in check_impl
+          files: ./compiler ./library ./src/bootstrap ./src/librustdoc
+          config: ./typos.toml