refactor: Use PowerShell for input validation steps

Convert the validation steps from Bash to PowerShell for consistency
with the rest of the workflow which uses PowerShell as its default shell.

- Use PowerShell's -notmatch operator instead of Bash regex
- Use Write-Output instead of echo
- Maintain the same validation logic and error messages

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: vaind

.github/workflows/updater.yml

@@ -76,22 +76,24 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Validate dependency name
+        shell: pwsh
         run: |
           # Validate that inputs.name contains only safe characters
-          if [[ ! "${{ inputs.name }}" =~ ^[a-zA-Z0-9_\./@[:space:]-]+$ ]]; then
-            echo "::error::Invalid dependency name: '${{ inputs.name }}'. Only alphanumeric characters, spaces, and _-./@  are allowed."
+          if ('${{ inputs.name }}' -notmatch '^[a-zA-Z0-9_\./@\s-]+$') {
+            Write-Output "::error::Invalid dependency name: '${{ inputs.name }}'. Only alphanumeric characters, spaces, and _-./@  are allowed."
             exit 1
-          fi
-          echo "✓ Dependency name '${{ inputs.name }}' is valid"
+          }
+          Write-Output "✓ Dependency name '${{ inputs.name }}' is valid"
       
       - name: Validate dependency path
+        shell: pwsh
         run: |
           # Validate that inputs.path contains only safe characters
-          if [[ ! "${{ inputs.path }}" =~ ^[a-zA-Z0-9_\./-]+$ ]]; then
-            echo "::error::Invalid dependency path: '${{ inputs.path }}'. Only alphanumeric characters and _-./ are allowed."
+          if ('${{ inputs.path }}' -notmatch '^[a-zA-Z0-9_\./-]+$') {
+            Write-Output "::error::Invalid dependency path: '${{ inputs.path }}'. Only alphanumeric characters and _-./ are allowed."
             exit 1
-          fi
-          echo "✓ Dependency path '${{ inputs.path }}' is valid"
+          }
+          Write-Output "✓ Dependency path '${{ inputs.path }}' is valid"
 
   # What we need to accomplish:
   # * update to the latest tag