In response to a request by CRAN, I have reduced the size of some of the test snapshots to reduce the overall tarball size.

## Test environments (with Github Actions)

* Windows 10.0.20348 (x86_64-w64-mingw32): R 4.4.1
* Mac OS X 14.6.1 (aarch64-apple-darwin20): R 4.4.1
* Ubuntu 22.04.4 (x86_64-pc-linux-gnu): R 4.3.3, 4.4.1, and devel (r87090)

## R CMD check results

0 errors | 0 warnings | 0 notes

## Downstream dependencies

We checked 2 reverse dependencies (1 from CRAN + 1 from Bioconductor), comparing R CMD check results across CRAN and dev versions of this package:

 * rmacrostrat (0.0.1)
 * orthogene (1.10.1)

### Dependency check results:
All packages passed.
