build(deps): Bump attestant/vouch in /testutil/compose/static/vouch

Bumps attestant/vouch from 1.9.0 to 1.9.2.

---
updated-dependencies:
- dependency-name: attestant/vouch
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

testutil/compose/static/vouch/Dockerfile

@@ -1,6 +1,6 @@
 FROM wealdtech/ethdo:1.35.2 as ethdo
 
-FROM attestant/vouch:1.9.0
+FROM attestant/vouch:1.9.2
 
 COPY --from=ethdo /app/ethdo /app/ethdo