.github/workflows: pin to action commit SHA (hashicorp#43610)

Author: jar-b

.github/workflows/smarterr.yml

@@ -42,7 +42,7 @@ jobs:
           path: ~/go/pkg/mod
           key: ${{ runner.os }}-go-pkg-mod-${{ hashFiles('go.sum') }}
       # long-running test
-      - uses: YakDriver/check-smarterr-config@v0.3.0 # v0.3.0
+      - uses: YakDriver/check-smarterr-config@6c840c1f0df56a8b550b159c7496770c28c75e51 # v0.3.0
         name: Check smarterr config
         with:
           base-dir: './internal'