Fix GitIgnore (#2491)

`ignore()` builds paths with leading `./`, e.g., `./path/to`, while
`load_recursive()` builds relative paths using `Path.relative_to()`,
which produces paths without `./`, e.g., `path/to`.

Fixes: #2485

Author: un-def

src/dstack/_internal/utils/ignore.py

@@ -20,6 +20,8 @@ def __init__(
         self.load_recursive()
 
     def load_ignore_file(self, path: str, ignore_file: Path):
+        if path != "." and not path.startswith("./"):
+            path = "./" + path
         if path not in self.ignore_globs:
             self.ignore_globs[path] = []
         with ignore_file.open("r") as f: