fix(ci): repin standards to a SHA that exists

Pinned hyperpolymath/standards@5b1d0022..., which DOES NOT EXIST (gh api
.../commits/<sha> -> 422). A workflow that cannot resolve its reusable
dies at startup_failure with zero jobs, producing no check runs -- which
is why required contexts such as 'governance / Validate Hypatia
Baseline' register as phantom and block every PR.

Repinned to d5fe075a (current standards main). Verified in hypatia#722
that this restores the workflows and the required context is produced.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: hyperpolymath

.github/workflows/hypatia-scan.yml

@@ -25,4 +25,4 @@ permissions:
 
 jobs:
   scan:
-    uses: hyperpolymath/standards/.github/workflows/hypatia-scan-reusable.yml@5b1d00229e5e8c0c0fbfedc7e80f37ea50f49236
+    uses: hyperpolymath/standards/.github/workflows/hypatia-scan-reusable.yml@d5fe075a50ab3ce4f41614d66ed77f152fda134f