ci(github): lowercase runner string in runners.yml

Author: remarkablemark

.github/workflows/runners.yml

@@ -15,13 +15,13 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
       - name: ${{ runner.os }}
-        run: echo $RUNNER_OS
+        run: echo ${RUNNER_OS@L}
 
   ubuntu-22-04:
     runs-on: ubuntu-22.04
     steps:
       - name: ${{ runner.os }}
-        run: echo $RUNNER_OS
+        run: echo ${RUNNER_OS,,}
 
   # Windows
   windows-latest:
@@ -36,14 +36,14 @@ jobs:
     steps:
       - name: ${{ runner.os }}
         shell: bash
-        run: echo $RUNNER_OS
+        run: echo ${RUNNER_OS@L}
 
   windows-2022:
     runs-on: windows-2022
     steps:
       - name: ${{ runner.os }}
         shell: bash
-        run: echo $RUNNER_OS
+        run: echo ${RUNNER_OS,,}
 
   # macOS
   macos-latest:
@@ -56,10 +56,10 @@ jobs:
     runs-on: macos-15
     steps:
       - name: ${{ runner.os }}
-        run: echo $RUNNER_OS
+        run: echo ${RUNNER_OS@L}
 
   macos-14:
     runs-on: macos-14
     steps:
       - name: ${{ runner.os }}
-        run: echo $RUNNER_OS
+        run: echo ${RUNNER_OS,,}