ci: pin supabase/sdk validate-capabilities workflow to v1.0.0

supabase/sdk cut its first tagged release, v1.0.0. Pin the reusable
validate-capabilities workflow ref to that release's commit SHA with a
version comment instead of a floating @main ref. Dependabot's
github-actions ecosystem (already configured here) picks up the
version comment and will open PRs to bump this as supabase/sdk cuts
new releases.

Author: grdsdev

.github/workflows/validate-capabilities.yml

@@ -12,7 +12,7 @@ permissions:
 
 jobs:
   validate:
-    uses: supabase/sdk/.github/workflows/validate-sdk-compliance-python.yml@main
+    uses: supabase/sdk/.github/workflows/validate-sdk-compliance-python.yml@93b52588ffda761e61b22cebfc3e5e29aa3cb3f4 # v1.0.0
     with:
       griffe-packages: >-
         supabase supabase_auth postgrest storage3 realtime supabase_functions