Make tags easier to match unknown CDs in Picard

Whipper added tags like "Unknown Album" that made matching harder, so
remove them. And add the discnumber tag, since that's known.

Author: dseomn

.local/bin/rip-cd

@@ -61,6 +61,18 @@ def main():
             "SOX_OPTS": "--single-threaded",
         },
     )
+    subprocess.run(
+        (
+            "metaflac",
+            "--remove-tag=album",
+            "--remove-tag=artist",
+            "--remove-tag=title",
+            f"--set-tag=discnumber={args.disc_number}",
+            "--",
+            *whipper_disc_path.glob("*.flac"),
+        ),
+        check=True,
+    )
     for whipper_file_path in tuple(whipper_disc_path.iterdir()):
         # TODO(https://github.com/python/cpython/issues/56950): Fix this race
         # condition.