Close RECORD after reading entries during uninstall (#2259)

## Summary

It turns out that by keeping the `RECORD` file open, older versions of
Windows mark it for deletion, but don't allow it to be deleted until
it's closed. As such, we end up leaving the `.dist-info` directory
around, since it appears non-empty; but once the program terminates, we
_do_ delete `RECORD`, leaving it empty. This then creates the impression
that a package exists where it does not.

Closes #2074.

crates/install-wheel-rs/src/uninstall.rs

@@ -16,15 +16,17 @@ pub fn uninstall_wheel(dist_info: &Path) -> Result<Uninstall, Error> {
     };
 
     // Read the RECORD file.
-    let record_path = dist_info.join("RECORD");
-    let mut record_file = match fs::File::open(&record_path) {
-        Ok(record_file) => record_file,
-        Err(err) if err.kind() == std::io::ErrorKind::NotFound => {
-            return Err(Error::MissingRecord(record_path));
-        }
-        Err(err) => return Err(err.into()),
+    let record = {
+        let record_path = dist_info.join("RECORD");
+        let mut record_file = match fs::File::open(&record_path) {
+            Ok(record_file) => record_file,
+            Err(err) if err.kind() == std::io::ErrorKind::NotFound => {
+                return Err(Error::MissingRecord(record_path));
+            }
+            Err(err) => return Err(err.into()),
+        };
+        read_record_file(&mut record_file)?
     };
-    let record = read_record_file(&mut record_file)?;
 
     let mut file_count = 0usize;
     let mut dir_count = 0usize;