Use Rust 1.78 for fmt and clippy in CI

Author: rnestler

.github/workflows/ci.yml

@@ -16,15 +16,15 @@ jobs:
 
   lint:
     runs-on: ubuntu-22.04
-    container: rust:1.69
+    container: rust:1.78
     steps:
       - uses: actions/checkout@v3
       - run: rustup component add clippy
       - run: cargo clippy --all-targets --all-features -- -D warnings
 
   fmt:
     runs-on: ubuntu-22.04
-    container: rust:1.69
+    container: rust:1.78
     steps:
       - uses: actions/checkout@v3
       - run: rustup component add rustfmt