Remove the custom Cargo configuration

In the move from Alpine Linux 3.17 to 3.18 we also moved from Cargo
1.64.0 to 1.71.1. This takes us past Rust 1.68 (since Cargo uses the
same version) which introduced sparse registries and as a result this
should resolve #38.

Author: mcdonnnj

Dockerfile

@@ -44,9 +44,6 @@ RUN apk --no-cache add \
   python3-dev=3.11.8-r0 \
   python3=3.11.8-r0
 
-# Copy in our custom Cargo configuration file
-COPY src/config.toml /root/.cargo/
-
 # Install pipenv to manage installing the Python dependencies into a created
 # Python virtual environment. This is done separately from the virtual
 # environment so that pipenv and its dependencies are not installed in the