Disable clang-tidy action in favor of clangd-tidy (#6037)

Generally seems to be working as intended: clang-tidy has variance from
a few minutes to an hour; clang-tidy hovers around 10 minutes. In this
case, the long tail of slow execution is more visible, partly because
tests will often take close to 10 minutes, if not more.

Branch enforcement should already be switched.

.github/workflows/clang_tidy.yaml

@@ -1,80 +0,0 @@
-# Part of the Carbon Language project, under the Apache License v2.0 with LLVM
-# Exceptions. See /LICENSE for license information.
-# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-
-name: 'Clang Tidy'
-
-on:
-  push:
-    branches: [trunk, action-test]
-  pull_request:
-  merge_group:
-
-permissions:
-  contents: read # For actions/checkout.
-  pull-requests: read # For dorny/paths-filter to read pull requests.
-
-# Cancel previous workflows on the PR when there are multiple fast commits.
-# https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#concurrency
-concurrency:
-  group: ${{ github.workflow }}-${{ github.head_ref || github.ref }}
-  cancel-in-progress: true
-
-jobs:
-  clang-tidy:
-    runs-on: ubuntu-22.04
-
-    steps:
-      - name: Harden Runner
-        uses: step-security/harden-runner@17d0e2bd7d51742c71671bd19fa12bdc9d40a3d6 # v2.8.1
-        with:
-          egress-policy: block
-          # When adding endpoints, see README.md.
-          # prettier-ignore
-          allowed-endpoints: >
-            *.dl.sourceforge.net:443
-            api.github.com:443
-            bcr.bazel.build:443
-            downloads.sourceforge.net:443
-            github.com:443
-            mirrors.kernel.org:443
-            nodejs.org:443
-            oauth2.googleapis.com:443
-            objects.githubusercontent.com:443
-            pypi.org:443
-            releases.bazel.build:443
-            sourceforge.net:443
-            storage.googleapis.com:443
-
-      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
-
-      - id: test-setup
-        uses: ./.github/actions/test-setup
-        with:
-          matrix_runner: 'ubuntu-22.04'
-          base_sha:
-            ${{ github.event_name == 'pull_request' &&
-            github.event.pull_request.base.sha ||
-            github.event.merge_group.base_sha }}
-          remote_cache_key: ${{ secrets.CARBON_BUILDS_GITHUB }}
-          targets_file: ${{ runner.temp }}/targets
-          use_direct_targets: true
-
-      # Run in the clang-tidy config. This is done as part of tests so that we
-      # aren't duplicating bazel/llvm setup.
-      #
-      # The `-k` flag is used to print all clang-tidy errors.
-      - name: clang-tidy
-        if: steps.test-setup.outputs.has_code == 'true'
-        env:
-          TARGETS_FILE: ${{ runner.temp }}/targets
-        run: |
-          ./scripts/run_bazel.py \
-              --attempts=5 \
-              build --config=clang-tidy -k \
-              --target_pattern_file=$TARGETS_FILE
-
-      # See "Disk space before build" in `test-setup`.
-      - name: Disk space after build
-        if: steps.test-setup.outputs.has_code == 'true'
-        run: df -h