Fix PowerShell script line endings for GitHub Actions

Change PowerShell scripts from CRLF to LF line endings to fix the build failure on Linux runners in GitHub Actions. The error was:
  /usr/bin/env: 'pwsh\r': No such file or directory

This occurred because CRLF line endings caused the shebang line to be interpreted incorrectly on Unix systems.

PowerShell Core (pwsh) works correctly with LF line endings on all platforms including Windows, so this change maintains cross-platform compatibility while fixing the CI build.

Author: claude

.gitattributes

@@ -19,8 +19,8 @@
 # Bash scripts should use LF
 *.sh text eol=lf
 
-# Powershell scripts should use CRLF
-*.ps1 text eol=crlf
+# PowerShell scripts should use LF (for cross-platform compatibility and GitHub Actions)
+*.ps1 text eol=lf
 
 # Documentation
 *.md text diff=markdown