IANAL and all, but here’s my take.
In my reading of the Creative Commons FAQ on CC licenses and software and related links, listing both a CC and Software license would mean that both apply to all content, unless explicitly indicated otherwise.
Version 4.0 of CC’s Attribution-ShareAlike (BY-SA) license is one-way compatible with the GNU General Public License version 3.0 (GPLv3). This compatibility mechanism is designed for situations in which content is integrated into software code in a way that makes it difficult or impossible to distinguish the two. There are special considerations required before using this compatibility mechanism. Read more about it here.
For instance, StackOverflow runs under a CC-BY-SA license, so technically if you re-use stuff from StackOverflow, you should probably use CC-BY-SA, and this would allow derivatives of your code to be released with a GPL license.
Note that I think the situation is somewhat simpler if your code & other content is all original to you and not encumbered by viral clauses of licenses like BY-SA or GPL. I think any CC-BY or CC-BY-SA would thus be fine for most Rmd notebooks etc, while the CC-*-ND licenses would clearly prevent re-use.
You can also declare CC0, which is valid for software and other content. Then your content is compatible with GPL, CC, or any other (open or otherwise) license someone wants to use downstream.
Because CC0 forgoes the “attribution” clause of CC-BY, I think as academics we often conflate that with waiving the expectation of citation. IMHO, citation is a question of academic norms and integrity that is wholly separate from the legal protections of copyright. (For instance, no one would argue it was okay to omit all citations to Newton or Shakespeare, whose works are all in the public domain).
CC0 also makes no mention of patent rights, except to say that it makes no mention of patent rights:
No trademark or patent rights held by Affirmer are waived, abandoned,
surrendered, licensed or otherwise affected by this document
For this reason, the Open Source Initiative does not recognize CC0 as an OSI license itself (as opposed to licenses like MIT & BSD, which simply avoid mentioning the word “patent” one way or another). Go figure.