[fix] Added graphviz dependency (Resolves #637)

[SaxenaAnushka102]

Added graphviz to requirements.txt

Resolves #637

BEGINRELEASENOTES

• Added missing dependency graphviz for podio-vis functionality in the documentation build process.

ENDRELEASENOTES

[tmadlener]

Thanks. A few minor comments.

[tmadlener]

This actually needs to go here and then we use pip-compile to generate the actual requirements.txt from there.

[SaxenaAnushka102]

@tmadlener Thanks for explaining, I've updated requirements.in . I'm sorry for adding the dependency to an auto-generated file 😅

[tmadlener]

Sorry, this might have been a bit confusing if you are not completely familiar with podios structure. There are actually two requirements.txt files:

• We have this requirements.txt at the top level. This is what is necessary to use podio and it's python bindings.
• We have another one in doc/requirements.txt. This is the one that is generated from the requirements.in in the same folder. These are the dependencies to generate and build the documentation of podio.

Hence, what you want to change for fixing the issue is the first one and not the requirements.in.

[tmadlener]

Suggested change

	sphinx_copybutton
	sphinx_copybutton

Simply to not touch this file in this PR.

edit: github doesn't really deal with this properly. the fix is to add a newline after sphinx_copybutton (same for the suggestion below).

[tmadlener]

Suggested change

	graphviz
	graphviz

Something in your editor settings seems to strip off the last newline in each file.

[SaxenaAnushka102]

Yes, you're right. I'll check for the new lines from next time. Thanks!

[tmadlener]

Thanks a lot for your work (and patience). Waiting for the CI to run to completion before merging.