Bump min Rust version

Author: lookback-hugotunius

.github/workflows/cargo.yml

@@ -16,7 +16,7 @@ jobs:
       matrix:
         os: ['ubuntu-latest', 'macos-latest', 'windows-latest']
         toolchain:
-          - 1.56.1 # min supported version (https://github.com/webrtc-rs/webrtc/#toolchain)
+          - 1.57.0 # min supported version (https://github.com/webrtc-rs/webrtc/#toolchain)
           - stable
     runs-on: ${{ matrix.os }}
     steps: