update ci for unused dep (#574)

.github/workflows/periodic_checks.yml

@@ -23,6 +23,4 @@ jobs:
       - name: Run cargo-udeps
         uses: aig787/cargo-udeps-action@v1
         with:
-          # not using --all-targets because --examples need "--features test-srs"
-          # checking the rest is sufficient for udeps purposes.
-          args: "--workspace --tests --lib --bins --benches"
+          args: "--workspace --all-targets --features 'test-srs test-apis bls schnorr gadgets'"