Workaround windows-gnu being broken on the current stable

See rust-lang/rust#67429 and related issues.

Author: lu-zero

.github/workflows/rav1e.yml

@@ -343,7 +343,7 @@ jobs:
     - name: Install cargo-c
       if: matrix.conf == 'cargo-c'
       run: |
-        cargo install cargo-c
+        rustup run --install stable-msvc cargo install cargo-c
     - name: Run cargo-c
       if: matrix.conf == 'cargo-c'
       run: |