Remove (bugggy) no-tests workarounds

The no-coverage-report special case hid real coverage build failures
unintentionally.

Author: nothingmuch

nix/checks.nix

@@ -28,7 +28,6 @@
           strictDeps = true;
           cargoArtifacts = deps;
           CARGO_PROFILE = profile;
-          cargoNextestExtraArgs = "--no-tests=warn";
         };
 
       testChecks = pkgs.lib.concatMapAttrs (
@@ -51,7 +50,7 @@
             nativeBuildInputs = [ pkgs.cargo-llvm-cov ];
             buildPhaseCargoCommand = ''
               mkdir -p $out
-              cargo llvm-cov nextest --no-tests=warn --all-features --lcov --output-path $out/coverage.lcov
+              cargo llvm-cov --all-features --lcov --output-path $out/coverage.lcov
               cargo llvm-cov report --fail-under-regions 100
             '';
             installPhase = "true";