Shellcheck: move excludes to action env

.github/workflows/lint.yml

@@ -1,10 +1,4 @@
-on:
-  push:
-    branches:
-    - master
-  pull_request:
-    branches:
-    - master
+on: push
 
 name: Lint
 
@@ -12,17 +6,17 @@ jobs:
   shellcheck:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
-    - name: shellcheck
-      uses: ludeeus/action-shellcheck@0.5.0
-      env:
-        SHELLCHECK_OPTS: -e SC1091,SC2164,SC2034,SC1072,SC1073,SC1009
+      - uses: actions/checkout@v2
+      - name: shellcheck
+        uses: ludeeus/action-shellcheck@0.5.0
+        env:
+          SHELLCHECK_OPTS: -e SC1091,SC2164,SC2034,SC1072,SC1073,SC1009
 
   shfmt:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
-    - name: shfmt
-      uses: bltavares/actions/shfmt@master
-      env:
-        SHFMT_ARGS: -d
+      - uses: actions/checkout@v2
+      - name: shfmt
+        uses: bltavares/actions/shfmt@master
+        env:
+          SHFMT_ARGS: -d