Split apart build and test CI jobs

Originally, the tests required the binary produced by 'cargo build', but
now that that's fixed, and the tests require code coverage
instrumentation (forcing a rebuild anyways), it's better to do the build
and test in parallel.

.github/workflows/lint.yml

@@ -44,6 +44,22 @@ jobs:
               run: cargo fmt -- --check --config group_imports=StdExternalCrate,imports_granularity=Module
 
     build:
+        runs-on: ubuntu-latest
+        steps:
+            - uses: actions/checkout@v4
+            - name: Setup Rust toolchain
+              uses: dtolnay/rust-toolchain@master
+              with:
+                toolchain: stable
+                components: clippy
+            - name: Setup Rust cache
+              uses: swatinem/rust-cache@v2
+            - name: Build
+              run: cargo build --all-targets --all-features
+            - name: Clippy
+              run: cargo clippy --no-deps --all-targets --all-features
+
+    test:
         runs-on: ubuntu-latest
         steps:
             - uses: actions/checkout@v4
@@ -58,10 +74,6 @@ jobs:
               uses: taiki-e/install-action@v2
               with:
                 tool: cargo-nextest,cargo-llvm-cov
-            - name: Build
-              run: cargo build --all-targets --all-features
-            - name: Clippy
-              run: cargo clippy --no-deps --all-targets --all-features
             - name: Test
               run: |
                   git fetch