Apply percent-decoding to file-based URLs (#1541)

## Summary

Closes https://github.com/astral-sh/uv/issues/1537.

crates/uv-fs/Cargo.toml

@@ -21,6 +21,7 @@ fs2 = { workspace = true }
 junction = { workspace = true }
 tempfile = { workspace = true }
 tracing = { workspace = true }
+urlencoding = { workspace = true }
 
 [features]
 default = []

crates/uv-fs/src/path.rs

@@ -31,14 +31,18 @@ impl<T: AsRef<Path>> Normalized for T {
 ///
 /// On other platforms, this is a no-op.
 pub fn normalize_url_path(path: &str) -> Cow<'_, str> {
+    // Apply percent-decoding to the URL.
+    let path = urlencoding::decode(path).unwrap_or(Cow::Borrowed(path));
+
+    // Return the path.
     if cfg!(windows) {
         Cow::Owned(
             path.strip_prefix('/')
-                .unwrap_or(path)
+                .unwrap_or(&path)
                 .replace('/', std::path::MAIN_SEPARATOR_STR),
         )
     } else {
-        Cow::Borrowed(path)
+        path
     }
 }
 
@@ -71,5 +75,17 @@ mod tests {
                 "./ferris/wheel-0.42.0.tar.gz"
             );
         }
+
+        if cfg!(windows) {
+            assert_eq!(
+                normalize_url_path("./wheel%20cache/wheel-0.42.0.tar.gz"),
+                ".\\wheel cache\\wheel-0.42.0.tar.gz"
+            );
+        } else {
+            assert_eq!(
+                normalize_url_path("./wheel%20cache/wheel-0.42.0.tar.gz"),
+                "./wheel cache/wheel-0.42.0.tar.gz"
+            );
+        }
     }
 }