Remove tidy key in PR CI

This avoids confusing error messages when adding an `auto` job to CI (as
recommended in the dev-guide: https://rustc-dev-guide.rust-lang.org/tests/ci.html#using-ci-to-test).

Author: jyn514

.github/workflows/ci.yml

@@ -42,24 +42,20 @@ jobs:
       TOOLSTATE_REPO: "https://github.com/rust-lang-nursery/rust-toolstate"
       CACHE_DOMAIN: ci-caches.rust-lang.org
     if: "github.event_name == 'pull_request'"
-    continue-on-error: "${{ matrix.tidy }}"
+    continue-on-error: "${{ matrix.name == 'mingw-check-tidy' }}"
     strategy:
       matrix:
         include:
           - name: mingw-check
-            tidy: false
             os: ubuntu-20.04-16core-64gb
             env: {}
           - name: mingw-check-tidy
-            tidy: true
             os: ubuntu-20.04-16core-64gb
             env: {}
           - name: x86_64-gnu-llvm-14
-            tidy: false
             os: ubuntu-20.04-16core-64gb
             env: {}
           - name: x86_64-gnu-tools
-            tidy: false
             os: ubuntu-20.04-16core-64gb
             env: {}
     timeout-minutes: 600

src/ci/github-actions/ci.yml

@@ -300,25 +300,21 @@ jobs:
     env:
       <<: [*shared-ci-variables, *public-variables]
     if: github.event_name == 'pull_request'
-    continue-on-error: ${{ matrix.tidy }}
+    continue-on-error: ${{ matrix.name == 'mingw-check-tidy' }}
     strategy:
       matrix:
         include:
           - name: mingw-check
             <<: *job-linux-16c
-            tidy: false
 
           - name: mingw-check-tidy
             <<: *job-linux-16c
-            tidy: true
 
           - name: x86_64-gnu-llvm-14
             <<: *job-linux-16c
-            tidy: false
 
           - name: x86_64-gnu-tools
             <<: *job-linux-16c
-            tidy: false
 
   auto:
     permissions: