ci: use the default macOS SDK at build time

.github/workflows/deploy.yml

@@ -33,11 +33,11 @@ jobs:
             name: starship-arm-unknown-linux-musleabihf.tar.gz
 
           - target: x86_64-apple-darwin
-            os: macOS-latest
+            os: macOS-11
             name: starship-x86_64-apple-darwin.tar.gz
 
           - target: aarch64-apple-darwin
-            os: macOS-latest
+            os: macOS-11
             name: starship-aarch64-apple-darwin.tar.gz
 
           - target: x86_64-pc-windows-msvc
@@ -81,9 +81,6 @@ jobs:
 
       - name: Build | Build
         uses: actions-rs/cargo@v1.0.3
-        # TODO: Remove this once it's the default
-        env:
-          SDKROOT: /Library/Developer/CommandLineTools/SDKs/MacOSX11.1.sdk
         with:
           command: build
           args: --release --locked --features tls-vendored --target ${{ matrix.target }}