ci: Simplify test command by using -p instead of --manifest-path

.github/workflows/appservice.yml

@@ -53,10 +53,10 @@ jobs:
         uses: actions-rs/cargo@v1
         with:
           command: clippy
-          args: --manifest-path crates/matrix-sdk-appservice/Cargo.toml ${{ matrix.cargo_args }} -- -D warnings
+          args: -p matrix-sdk-appservice ${{ matrix.cargo_args }} -- -D warnings
 
       - name: Test
         uses: actions-rs/cargo@v1
         with:
           command: test
-          args: --manifest-path crates/matrix-sdk-appservice/Cargo.toml ${{ matrix.cargo_args }}
+          args: -p matrix-sdk-appservice ${{ matrix.cargo_args }}

xtask/src/ci.rs

@@ -120,9 +120,7 @@ fn run_feature_tests(cmd: Option<FeatureSet>) -> Result<()> {
     ]);
 
     let run = |arg_set: &str| {
-        cmd!("rustup run stable cargo test --manifest-path crates/matrix-sdk/Cargo.toml")
-            .args(arg_set.split_whitespace())
-            .run()
+        cmd!("rustup run stable cargo test -p matrix-sdk").args(arg_set.split_whitespace()).run()
     };
 
     match cmd {