build(docker): don't include Cargo.lock in image

Dockerfile

@@ -3,7 +3,7 @@
 FROM git.kemitix.net/kemitix/git-next-builder:latest AS builder
 WORKDIR /app
 
-COPY Cargo.toml Cargo.lock ./
+COPY Cargo.toml ./
 COPY src src
 RUN cargo chef prepare --recipe-path recipe.json
 
@@ -11,7 +11,7 @@ ARG CARGO_PROFILE
 # Build dependencies - this is the caching Docker layer!
 RUN cargo chef cook --profile "$CARGO_PROFILE" --recipe-path recipe.json
 # Build application
-COPY Cargo.toml Cargo.lock ./
+COPY Cargo.toml ./
 COPY src src
 ARG CARGO_PROFILE
 RUN cargo build --profile "$CARGO_PROFILE" --bin git-next