alpine: fix pyarrow name again

.docker/Dockerfile.alpine

@@ -19,11 +19,12 @@ RUN apk add --no-cache \
 
 FROM base AS builder
 
+# Yes it really is python3-dev, and py3-package
 RUN apk add --no-cache \
     ca-certificates \
     git \
     python3-dev \
-    python3-pyarrow \
+    py3-pyarrow \
     curl
 
 COPY . /app
@@ -34,7 +35,6 @@ COPY --from=ghcr.io/astral-sh/uv:0.5.5 /uv /uvx /bin/
 
 ENV UV_COMPILE_BYTECODE=1 UV_LINK_MODE=copy
 
-# Instead of restarting the shell, use uv directly from its installed location.
 RUN uv sync --extra test --extra webservice --extra watcher --no-dev
 
 FROM base