chore: use default target when building on unknown-linux-gnu

Signed-off-by: KtorZ <[email protected]>

Author: KtorZ

.github/workflows/CI.yml

@@ -105,7 +105,11 @@ jobs:
             # cross doesn't load .cargo/config.toml, see https://github.com/cross-rs/cross/issues/562
             $HOME/.cargo/bin/cross $COMMAND --locked --all-features $SCOPE --target ${{ matrix.environments.target }}
           else
-            cargo $EXTRA_ARGS $COMMAND $SCOPE --locked --target ${{ matrix.environments.target }}
+            if [[ "${{ matrix.environments.target }}" == "x86_64-unknown-linux-gnu" ]] ; then
+              cargo $EXTRA_ARGS $COMMAND $SCOPE --locked
+            else
+              cargo $EXTRA_ARGS $COMMAND $SCOPE --locked --target ${{ matrix.environments.target }}
+            fi
           fi
           exitcode="$?"
           if [[ "${{ matrix.environments.optional }}" == "true" && "$exitcode" != "0" ]] ; then
@@ -180,7 +184,7 @@ jobs:
 
       - name: Build Amaru
         run: |
-          cargo test --no-run -p amaru --target x86_64-unknown-linux-gnu
+          cargo test --no-run -p amaru
 
       - name: Cache Amaru's ledger.db
         id: cache-ledger-db