build(py-docker): Broken Debian SVG image convert

Apparently, [the Debian/Ubuntu build of ImageMagick doesn't enable
RSVG](readthedocs/readthedocs-docker-images#131 (comment))
so we have to use the much larger inkscape dependency:

:1+./.tox/py311/bin/sphinx-build -b latex -Wn -j auto -D autosummary_generate=0 -D autoapi_generate_api_docs=0 ./docs/ ./build/docs/latex/

Extension error:
convert exited with error:
[stderr]
b"convert-im6.q16: unrecognized color `d5d5d5' @ warning/color.c/GetColorCompliance/1057.\nconvert-im6.q16: non-conforming drawing primitive definition `stroke' @ error/draw.c/RenderMVGContent/4404.\n"
[stdout]
b''
make: *** [Makefile:376: build-docs-latex] Error 2

Dockerfile

@@ -122,7 +122,7 @@ RUN --mount=type=cache,target=/var/cache/apt,sharing=locked \
     --mount=type=cache,target=/var/lib/apt,sharing=locked \
     apt-get install --no-install-recommends -y \
     "texinfo=6.8-6+b1" "texlive=2022.20230122-3" "latexmk=1:4.79-1" \
-    "ghostscript=10.0.0~dfsg-11+deb12u3" "pipx=1.1.0-1"
+    "ghostscript=10.0.0~dfsg-11+deb12u3" "inkscape=1.2.2-2+b1" "pipx=1.1.0-1"
 
 # Bake in tools used in the inner loop of the development cycle:
 # hadolint ignore=DL3042