Bump lib/spm_2_bids from 0a8cba6 to bc20418

Bumps [lib/spm_2_bids](https://github.com/cpp-lln-lab/spm_2_bids) from `0a8cba6` to `bc20418`.
- [Release notes](https://github.com/cpp-lln-lab/spm_2_bids/releases)
- [Commits](cpp-lln-lab/spm_2_bids@0a8cba6...bc20418)

---
updated-dependencies:
- dependency-name: lib/spm_2_bids
  dependency-version: bc20418c7e9ab5a234099d8d5a8d8673ed185779
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]