fix: Provide libc for pydantic

Fixes:

```
ImportError: Error loading shared library libgcc_s.so.1: No such file or
directory (needed by
/app/.venv/lib/python3.10/site-packages/pydantic_core/_pydantic_core.cpython-310
-x86_64-linux-gnu.so)
```

Suppose that with pydantic v2 and its Rust core,
Alpine + musl doesn't cut it anymore

Dockerfile

@@ -18,16 +18,15 @@ COPY . .
 
 RUN poetry install --only main
 
-FROM python:3.10-alpine
+FROM python:3.10
 
 ARG WORKDIR
 
 WORKDIR ${WORKDIR}
 
 COPY --from=builder ${WORKDIR} .
 
-# For options, see https://boxmatrix.info/wiki/Property:adduser
-RUN adduser app -DHh ${WORKDIR} -u 1000
+RUN useradd -u 1000 -d ${WORKDIR} -M app
 USER 1000
 
 # App-specific settings: