Fix this snapshot bug and then fix the 0.4.5 release

[sjspielman]

I had released 0.4.5 but then got a very surprising R CMD CHECK failure related to anndata snapshot checks which I tried to address here: #336

However, this did not do the trick, and it seems like this is still related to caching somehow but differently. https://github.com/AlexsLemonade/scpcaTools/actions/runs/23918657040

2026-04-02T20:20:48.6879068Z ══ Failed tests ════════════════════════════════════════════════════════════════
2026-04-02T20:20:48.6879737Z ── Failure ('test-sce_to_anndata.R:41:3'): Conversion of SCE to AnnData works as expected ──
2026-04-02T20:20:48.6880350Z Adding new file snapshot: 'tests/testthat/_snaps/sce_to_anndata/anndata.h5'
2026-04-02T20:20:48.6881021Z ── Failure ('test-sce_to_anndata.R:76:3'): Conversion of SCE to AnnData works as expected ──
2026-04-02T20:20:48.6881618Z Adding new file snapshot: 'tests/testthat/_snaps/sce_to_anndata/new_anndata.h5'
2026-04-02T20:20:48.6882580Z ── Failure ('test-sce_to_anndata.R:98:3'): Conversion of SCE to AnnData works with additional arguments ──
2026-04-02T20:20:48.6883267Z Adding new file snapshot: 'tests/testthat/_snaps/sce_to_anndata/no_verbose_anndata.h5'
2026-04-02T20:20:48.6883585Z
2026-04-02T20:20:48.6883909Z ── Snapshots ───────────────────────────────────────────────────────────────────
2026-04-02T20:20:48.6884299Z To review and process snapshots locally:
2026-04-02T20:20:48.6886201Z * Run testthat::snapshot_download_gh("AlexsLemonade/scpcaTools", "23918657040") to download snapshots.
2026-04-02T20:20:48.6886838Z * Run testthat::snapshot_accept() to accept all changes.
2026-04-02T20:20:48.6887438Z * Run testthat::snapshot_review() to review

I'm sort of surprised at this point that these snapshot tests ever passed in CI, since we don't store them in _snaps and the errors seem like it wants some interactivity.

I'm tempted to rip out snapshot testing and just make sure the file was created, but first I'd like to figure out more clearly what's going on here. Either way, we would like to fix this and then delete/remake the v0.4.5 release.

[sjspielman]

I wondered if this a testthat version situation. Our renv has 3.2.1.1 and this passes CI in PRs.
But it failed when merging where 3.2.2 was installed. The release notes looked promising - https://testthat.r-lib.org/news/index.html#testthat-322

But then again the actual diff for expect_snapshot_file() does not look as promising! r-lib/testthat@v3.2.1...v3.2.2

...Of course on the other hand, it failed here too where 3.2.1.1 was installed which is quite unpromising: https://github.com/AlexsLemonade/scpcaTools/actions/runs/23907476828/job/69720151193

It was a nice idea while it lasted!

[sjspielman]

I wondered if this a testthat version situation. Our renv has 3.2.1.1 and this passes CI in PRs. But it failed when merging where 3.2.2 was installed. The release notes looked promising - https://testthat.r-lib.org/news/index.html#testthat-322

But then again the actual diff for expect_snapshot_file() does not look as promising! r-lib/testthat@v3.2.1...v3.2.2

...Of course on the other hand, it failed here too where 3.2.1.1 was installed which is quite unpromising: https://github.com/AlexsLemonade/scpcaTools/actions/runs/23907476828/job/69720151193

It was a nice idea while it lasted!

Aha! I can't read, which in the current circumstance is good news.

1. The failed runs installed 3.3.2 not 3.2.2. I'm more inclined to believe this is the culprit.
2. "Of course on the other hand, it failed here too " no, it didn't. This was a legit bug so failing was expected, but the bug was addressed in that PR.

I dug in a bit more to convince myself. There look to be specific changes in 3.3.2 related* to CI failures that aren't in 3.2.1.
See 3.2.2: https://github.com/r-lib/testthat/blob/v3.3.2/R/snapshot.R
Vs 3.2.1: https://github.com/r-lib/testthat/blob/v3.2.1/R/snapshot.R

As such, we're good! The failure here is a not surprising consequence of version differences when running not in our renv environment.