ci: improve caching of build artifacts (#41)

* ci: add `--target` to `cargo test`

I noticed in GH Action output that `cargo test` is compiling our
dependencies again. Maybe it is not correctly reusing the cache?

In this commit, I am adding `--target` flag to `cargo test`, using
the same value that was provided to `cargo build` which is producing
the build artifacts saved to the cache.

Signed-off-by: Miroslav Bajtoš <oss@bajtos.net>

* ci: build all targets (bins, libs, tests, etc.)

I noticed in GH Action output that `cargo test` is compiling our
dependencies again. Maybe the build step did not compile everything
that's needed by our tests?

In this commit, I am adding `--all-targets` flag to `cargo build`,
hoping that the subsequent `cargo test` will not need to compile
anything.

Signed-off-by: Miroslav Bajtoš <oss@bajtos.net>

---------

Signed-off-by: Miroslav Bajtoš <oss@bajtos.net>

.github/workflows/ci.yaml

@@ -42,7 +42,7 @@ jobs:
           # save-if: ${{ github.ref == 'refs/heads/main' }}
 
 
-      - run: cargo build --workspace --all-features --target=${{ matrix.target }}
+      - run: cargo build --workspace --all-features --all-targets --target=${{ matrix.target }}
 
   test:
     name: Test ${{ matrix.crate }}
@@ -75,7 +75,7 @@ jobs:
           save-if: false
 
       - name: Run all tests
-        run: cargo test --package ${{ matrix.crate }} --all-features
+        run: cargo test --package ${{ matrix.crate }} --all-features --target=${{ matrix.target }}
 
       # - name: Check if we compile without any features activated
       #   run: cargo build --package ${{ matrix.crate }} --no-default-features