👷 add CI steps for Clang-Tidy

.github/workflows/macos.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: macos-latest
 
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - name: cmake
       run: cmake -S . -B build -D CMAKE_BUILD_TYPE=Debug -DJSON_BuildTests=On
     - name: build

.github/workflows/ubuntu.yml

@@ -6,7 +6,7 @@ jobs:
   ci_test_clang_cxx20:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - name: install_clang
       run: |
         sudo apt update
@@ -20,7 +20,7 @@ jobs:
   ci_clang_analyze:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - name: install_ninja
         run: |
           sudo apt update
@@ -41,7 +41,7 @@ jobs:
   ci_test_clang:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - name: install_ninja
         run: |
           sudo apt update
@@ -92,7 +92,7 @@ jobs:
   ci_cpplint:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - name: cmake
         run: cmake -S . -B build -DJSON_CI=On
       - name: build
@@ -100,20 +100,9 @@ jobs:
 
   ci_clang_tidy:
     runs-on: ubuntu-latest
+    container: nlohmann/json-ci:latest
     steps:
-      - uses: actions/checkout@v1
-      - name: install_ninja
-        run: |
-          sudo apt update
-          sudo apt install ninja-build
-        shell: bash
-      - name: install_clang
-        run: |
-          wget https://apt.llvm.org/llvm.sh
-          chmod +x llvm.sh
-          sudo ./llvm.sh 11
-          sudo apt-get install clang-tools-11
-        shell: bash
+      - uses: actions/checkout@v2
       - name: cmake
         run: cmake -S . -B build -DJSON_CI=On
       - name: build

.github/workflows/windows.yml

@@ -7,7 +7,7 @@ jobs:
     runs-on: windows-latest
 
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - name: cmake
       run: cmake -S . -B build -G "Visual Studio 16 2019" -D CMAKE_BUILD_TYPE=Debug -DJSON_BuildTests=On
     - name: build
@@ -19,7 +19,7 @@ jobs:
     runs-on: windows-latest
 
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - name: install Clang
         run: curl -fsSL -o LLVM10.exe https://github.com/llvm/llvm-project/releases/download/llvmorg-10.0.0/LLVM-10.0.0-win64.exe ; 7z x LLVM10.exe -y -o"C:/Program Files/LLVM"
       - name: cmake
@@ -33,7 +33,7 @@ jobs:
     runs-on: windows-latest
 
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - name: cmake
         run: cmake -S . -B build -G "Visual Studio 16 2019" -A x64 -T ClangCL -DJSON_BuildTests=On
       - name: build
@@ -45,7 +45,7 @@ jobs:
     runs-on: windows-latest
 
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - name: cmake
         run: cmake -S . -B build -G "Visual Studio 16 2019" -A Win32 -T ClangCL -DJSON_BuildTests=On
       - name: build