Prepare for scpca-nf release `v0.8.5`

Steps for a new release of `scpca-nf`

[x] Are all of the issues planned for this release resolved? If there are any issues that are unresolved, mark this issue as blocked by those on ZenHub.
[x] Update code and documentation with the latest version number in the development branch:
- [x] nextflow.config
- [x] internal-instructions.md
- [x] external-instructions.md
[x] Test that the workflow is in good working order with nextflow run alexslemonade/scpca-nf -latest -r development
[x] File a PR from the development branch to the main branch. This should include all of the changes that will be associated with the next release.
[x] (Optional) Generate new example scpca-nf output files. If updating the example output is not necessary for this release, check these boxes off for free.
- [x] Re-process the example data through the scpca-nf workflow and ensure it looks correct.
- [x] Compress the example output in scpca_out to create scpca_out.zip, as described in the instructions, and ensure the file is set to public and read-only.

[x] On the releases page, choose Draft a new release.
[x] In Choose a tag, type a new release number using semantic versioning (vX.X.X) (you did update the title of this issue to match, right?), then click Create a new tag: vX.X.X on publish.
[x] Write a description of the major changes in this release. You may want to start with the auto-generated release notes to save time.
[x] Optional: If not all issues have been addressed, save a draft to return to later.
[x] Publish the release!