Fix: cargo-check-external-types must use nightly 2023-10-10

Signed-off-by: Matthias Beyer <[email protected]>

Author: matthiasbeyer

.github/workflows/external-types.yml

@@ -13,7 +13,7 @@ jobs:
       - name: Install toolchain
         uses: dtolnay/rust-toolchain@master
         with:
-          toolchain: nightly
+          toolchain: nightly-2023-10-10
 
       - name: Install cargo-check-external-types
         run: cargo install --locked cargo-check-external-types