Update Rust toolchain to 1.83 in CI

.gitea/images/Dockerfile

@@ -1,4 +1,4 @@
-FROM docker.io/library/rust:1.80
+FROM docker.io/library/rust:1.83
 
 RUN rustup component add \
   clippy \

.gitea/workflows/gitea-ci.yaml

@@ -7,13 +7,14 @@ on:
     branches: [ main ]
 
 env:
+  CI_CONTAINER: docker.io/drrobot/musichoard-ci:20241230-1
   CARGO_TERM_COLOR: always
   CARGO_TERM_VERBOSE: true
 
 jobs:
   build_and_test:
     name: Build and Test
-    container: docker.io/drrobot/musichoard-ci:20240824-1
+    container: ${{ env.CI_CONTAINER }}
     env:
       BEETSDIR: ./
       LLVM_PROFILE_FILE: target/debug/profraw/musichoard-%p-%m.profraw
@@ -48,7 +49,7 @@ jobs:
 
   lint:
     name: Lint
-    container: docker.io/drrobot/musichoard-ci:20240824-1
+    container: ${{ env.CI_CONTAINER }}
     steps:
       - uses: actions/checkout@v3
       - run: cargo clippy --no-default-features --all-targets -- -D warnings