Fix git fetch tag conflicts on case-insensitive filesystems

[Copilot]

Build workflows failed on Windows/macOS when fetching tags due to repository containing both V4.10.8 and v4.10.8. Case-insensitive filesystems cannot distinguish these references, causing git fetch --tags to fail with reference conflicts.

Changes

• Modified tag existence checks to fetch specific tags instead of all tags
• Check local refs first (already available from checkout), then fetch individually if needed
• Applied to all three platform workflows: Windows, macOS, Linux

Before

git fetch --tags origin  # Fails on case-insensitive FS
if git rev-parse --verify --quiet "refs/tags/$TAG" >/dev/null; then

After

# Check local first, then fetch specific tag only
if git rev-parse --verify --quiet "refs/tags/$TAG" 2>/dev/null; then
  echo "Found locally"
else
  git fetch origin "refs/tags/$TAG:refs/tags/$TAG" 2>/dev/null
fi

This eliminates the filesystem conflict while preserving tag validation functionality.

Original prompt

https://github.com/TanNhatCMS/FlyEnv/actions/runs/20006714350 fix lỗi build này và bạn có thể build thử không

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