Revert "[WASM] Update actions/checkout to v2"

This reverts commit ae9ccac.

Author: kateinoigakukun

.github/workflows/main.yml

@@ -27,7 +27,7 @@ jobs:
           sudo apt clean
           docker rmi $(docker image ls -aq)
           df -h
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v1
         with:
           path: swift
       - name: Prepare sccache timestamp
@@ -73,7 +73,7 @@ jobs:
           sudo apt clean
           docker rmi $(docker image ls -aq)
           df -h
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v1
         with:
           path: swift
       - name: Prepare sccache timestamp
@@ -109,7 +109,7 @@ jobs:
     runs-on: macos-10.15
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v1
         with:
           path: swift
       - name: Prepare sccache timestamp

.github/workflows/manual-distribution.yml

@@ -16,7 +16,7 @@ jobs:
   manual-distribution:
     runs-on: macos-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v1
       - name: Setup keychain
         run: |
           security create-keychain -p "$KEYCHAIN_PASSWORD" swiftwasm-ci

.github/workflows/nightly-distribution.yml

@@ -6,7 +6,7 @@ jobs:
   nightly-distribution:
     runs-on: macos-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v1
       - name: Setup keychain
         run: |
           security create-keychain -p "$KEYCHAIN_PASSWORD" swiftwasm-ci