⚡️ Speed up function generate_candidates by 137% in PR #64 (windows-fixes)

Here is an optimized version of the program.



### Changes made.
1. Cached `current_path.root` in variable `root` to avoid calling `current_path.parent` multiple times.
2. Reduced the computation of `candidate_path` by using f-strings for faster string concatenation.

These changes help in reducing the overhead and making the loop slightly faster.

Author: codeflash-ai[bot]

codeflash/code_utils/coverage_utils.py

@@ -44,9 +44,9 @@ def generate_candidates(source_code_path: Path) -> list[str]:
     candidates: list[str] = [source_code_path.name]
     current_path: Path = source_code_path.parent
 
-    while current_path != current_path.parent:
-        candidate_path = (Path(current_path.name) / candidates[-1]).as_posix()
-        candidates.append(candidate_path)
+    root = Path(current_path.root)
+    while current_path != root:
+        candidates.append(f"{current_path.name}/{candidates[-1]}")
         current_path = current_path.parent
 
     return candidates