GH Actions: consistently use actions/checkout@v2

.github/workflows/gen_bindings.yml

@@ -6,7 +6,7 @@ jobs:
   test-windows:
       runs-on: windows-latest
       steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - name: test_win
         run: |
           cd tests
@@ -16,7 +16,7 @@ jobs:
   test-mac:
       runs-on: macos-latest
       steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - uses: seanmiddleditch/gha-setup-ninja@master
       - name: test_macos
         run: |
@@ -26,7 +26,7 @@ jobs:
   test-linux:
       runs-on: ubuntu-latest
       steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - uses: seanmiddleditch/gha-setup-ninja@master
       - name: prepare
         run: |

.github/workflows/main.yml

@@ -6,7 +6,7 @@ jobs:
     windows:
         runs-on: windows-latest
         steps:
-        - uses: actions/checkout@v1
+        - uses: actions/checkout@v2
         - name: test_win
           run: |
             cd tests
@@ -15,7 +15,7 @@ jobs:
     mac:
         runs-on: macos-latest
         steps:
-        - uses: actions/checkout@v1
+        - uses: actions/checkout@v2
         - uses: seanmiddleditch/gha-setup-ninja@master
         - name: test_macos
           run: |
@@ -24,7 +24,7 @@ jobs:
     ios:
         runs-on: macos-latest
         steps:
-        - uses: actions/checkout@v1
+        - uses: actions/checkout@v2
         - name: test_ios
           run: |
             cd tests
@@ -32,7 +32,7 @@ jobs:
     linux:
         runs-on: ubuntu-latest
         steps:
-        - uses: actions/checkout@v1
+        - uses: actions/checkout@v2
         - uses: seanmiddleditch/gha-setup-ninja@master
         - name: prepare
           run: |
@@ -45,7 +45,7 @@ jobs:
     emscripten:
         runs-on: ubuntu-latest
         steps:
-        - uses: actions/checkout@v1
+        - uses: actions/checkout@v2
         - uses: seanmiddleditch/gha-setup-ninja@master
         - name: test_emscripten
           run: |
@@ -54,7 +54,7 @@ jobs:
     android:
         runs-on: ubuntu-latest
         steps:
-        - uses: actions/checkout@v1
+        - uses: actions/checkout@v2
         - uses: seanmiddleditch/gha-setup-ninja@master
         - uses: actions/setup-java@v1
           with:
@@ -66,7 +66,7 @@ jobs:
     uwp:
         runs-on: windows-latest
         steps:
-        - uses: actions/checkout@v1
+        - uses: actions/checkout@v2
         - name: test_uwp
           run: |
             cd tests