CI: Generate the lockfile before settingup the MSRV compiler

ammend previous commit

Author: ogoffart

.github/workflows/rust.yml

@@ -27,16 +27,16 @@ jobs:
 
     steps:
     - uses: actions/checkout@v3
-    - uses: dtolnay/rust-toolchain@stable
-      with:
-          toolchain: ${{ matrix.rust }}
-          components: rustfmt, clippy
     - name: Install nightly for minimal-versions
       if: matrix.rust == '1.65.0'
       uses: dtolnay/rust-toolchain@nightly
     - name: Generate minimal-versions lockfile
       if: matrix.rust == '1.65.0'
       run: cargo +nightly -Z minimal-versions generate-lockfile
+    - uses: dtolnay/rust-toolchain@stable
+      with:
+          toolchain: ${{ matrix.rust }}
+          components: rustfmt, clippy
     - name: Build
       run: cargo build --verbose
     - name: Run tests