drill(0.4.1): rewrite the self-ref pin to the candidate SHA

The pure consumer path cannot resolve CEREMONY_SELF_REF: "0.4.1" before
the candidate creates that tag, and release.yml's self-checkout is
hardcoded to heavy-duty/ceremony — so the pin is rewritten to the
candidate SHA, which resolves there today. Drill scaffolding only; this
ref is never merged.

.github/workflows/labels.yml

@@ -28,7 +28,7 @@ on:
 env:
   # A called workflow arrives without its repository. Keep this literal pin
   # aligned with the ceremony release consumed by callers (issue #9 D3).
-  CEREMONY_SELF_REF: "0.4.1"
+  CEREMONY_SELF_REF: "9a229ee643291c27dbd404fa97e4dcc7e6ed3b17"
 
 jobs:
   scope:

.github/workflows/release.yml

@@ -129,7 +129,7 @@ env:
   # `ref:` accepts ${{ env }}; `uses:` strings do not — which is why the
   # shared logic arrives as script files via checkout, not as inner `uses:`
   # references.
-  CEREMONY_SELF_REF: "0.4.1"
+  CEREMONY_SELF_REF: "9a229ee643291c27dbd404fa97e4dcc7e6ed3b17"
   VERSION_SOURCE: ${{ inputs.version-source }}
 
 jobs: