CI: Fix benchmark collection

The benchmark action's "cargo" tooling assumes the standard bencher
output format, and can't parse criterion's output. Fortunately,
criterion can also provide bencher output for compatibility.

In order to pass criterion flags via `cargo bench`, we need to ensure
that all benchmarks use it (otherwise the flags are rejected by the
built-in benchmark harness as unknown). Since we don't actually have any
benchmarks inside the library itself, we simply disable its benchmark
harness.

.github/workflows/bench.yml

@@ -19,7 +19,7 @@ jobs:
           toolchain: 1.51.0
           override: true
       - name: Run benchmark
-        run: cargo bench | tee output.txt
+        run: cargo bench -- --output-format bencher | tee output.txt
       - name: Store benchmark result
         uses: benchmark-action/github-action-benchmark@v1
         with:

Cargo.toml

@@ -56,6 +56,9 @@ dev-graph = ["plotters", "tabbycat"]
 gadget-traces = ["backtrace"]
 sanity-checks = []
 
+[lib]
+bench = false
+
 [[example]]
 name = "circuit-layout"
 required-features = ["dev-graph"]