Dedup default shell specification for GHA

.github/workflows/main.yml

@@ -4,6 +4,10 @@ on:
   - push
   - pull_request
 
+defaults:
+  run:
+    shell: bash
+
 jobs:
   rustfmt:
     runs-on: ubuntu-latest
@@ -30,10 +34,6 @@ jobs:
     runs-on: ${{ matrix.os }}
     timeout-minutes: 60
 
-    defaults:
-      run:
-        shell: bash
-
     strategy:
       fail-fast: false
       matrix:
@@ -129,10 +129,6 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 60
 
-    defaults:
-      run:
-        shell: bash
-
     steps:
     - uses: actions/checkout@v4
 
@@ -155,10 +151,6 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 60
 
-    defaults:
-      run:
-        shell: bash
-
     steps:
     - uses: actions/checkout@v4
 
@@ -190,10 +182,6 @@ jobs:
     runs-on: ${{ matrix.os }}
     timeout-minutes: 60
 
-    defaults:
-      run:
-        shell: bash
-
     strategy:
       fail-fast: false
       matrix: