Update a-mir-formality.md

Author: nikomatsakis

src/2025h2/a-mir-formality.md

@@ -6,7 +6,7 @@
 | Teams            | <!-- TEAMS WITH ASKS -->                                                         |
 | Task owners      | <!-- TASK OWNERS -->                                                             |
 | Status           | Proposed                                                                         |
-| Tracking issue   | *if this is a continuing goal, add the old tracking issue, else leave blank*     |
+| Tracking issue   | [rust-lang/rust-project-goals#122]                                               |
 | Zulip channel    | N/A (an existing stream can be re-used or new streams can be created on request) |
 
 ## Summary