build(deps): bump third_party/prjxray from `3265766` to `6f449c6` (#3817)

Bumps [third_party/prjxray](https://github.com/f4pga/prjxray) from `3265766` to `6f449c6`.
- [Commits](https://github.com/f4pga/prjxray/compare/326576604b8c011f67d68b8b3c427ba4d45783a2...6f449c6dda80a13f1e0fb66d870e67738615a255)

---
updated-dependencies:
- dependency-name: third_party/prjxray
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
diff --git a/third_party/prjxray b/third_party/prjxray
index 3265766..6f449c6 160000
--- a/third_party/prjxray
+++ b/third_party/prjxray
@@ -1 +1 @@
-Subproject commit 326576604b8c011f67d68b8b3c427ba4d45783a2
+Subproject commit 6f449c6dda80a13f1e0fb66d870e67738615a255