ci: add Swatinem/rust-cache to pull-request test and clippy jobs

Author: Algorithm5838

.github/workflows/pull-request.yml

@@ -25,6 +25,9 @@ jobs:
         uses: dtolnay/rust-toolchain@stable
         with:
           toolchain: stable
+
+      - name: Cache Cargo dependencies
+        uses: Swatinem/rust-cache@v2
 
       - name: Install cargo-nextest
         uses: taiki-e/install-action@nextest
@@ -63,5 +66,8 @@ jobs:
           toolchain: stable
           components: clippy
 
+      - name: Cache Cargo dependencies
+        uses: Swatinem/rust-cache@v2
+
       - name: Run cargo clippy
-        run: cargo clippy -- -D warnings
+        run: cargo clippy -- -D warnings