edit workflow to not use actions

Signed-off-by: Curtis Harding <curtis.harding@iohk.io>

.github/workflows/pull-request.yml

@@ -63,20 +63,17 @@ jobs:
         with:
           xcode-version: '15.0.1'
 
-      - name: "Install rust toolchain"
-        uses: actions-rs/toolchain@v1
-        with:
-          profile: minimal
-          toolchain: stable
-          override: true
+      - name: "Install rust toolchain (Linux)"
+        if: matrix.os-type == 'linux'
+        run: sudo apt install rustc -y
+
+      - name: "Install rust toolchain (Macos)"
+        if: matrix.os-type == 'macos'
+        run: brew install rustup
 
       - name: "Install wasm-pack"
-        uses: actions-rs/cargo@v1
-        with:
-          command: install
-          args: wasm-pack
+        run: cargo install wasm-pack
 
-
       - name: "Test Kotlin code is properly formatted"
         run: ./gradlew ktlintCheck