Fix source code linker for python sphinx build

Signed-off-by: Nicolae Dicu <nicolae.dicu.ext@qorix.ai>

Author: nicu1989

src/extensions/score_source_code_linker/generate_source_code_links_json.py

@@ -38,12 +38,16 @@ def find_git_root(start_path: str | Path = "") -> Path | None:
     """Find the git root directory starting from the given path or __file__."""
     if start_path == "":
         start_path = __file__
-
     git_root = Path(start_path).resolve()
     while not (git_root / ".git").exists():
         git_root = git_root.parent
         if git_root == Path("/"):
-            return None
+            # fallback to cwd when building with python -m sphinx docs _build -T
+            git_root = Path.cwd().resolve()
+            while not (git_root / ".git").exists():
+                git_root = git_root.parent
+                if git_root == Path("/"):
+                    return None
     return git_root