Bump test/fixtures/prism from b35e37b to 1b2e2a6

Bumps [test/fixtures/prism](https://github.com/ruby/prism) from `b35e37b` to `1b2e2a6`.
- [Release notes](https://github.com/ruby/prism/releases)
- [Commits](ruby/prism@b35e37b...1b2e2a6)

---
updated-dependencies:
- dependency-name: test/fixtures/prism
  dependency-version: 1b2e2a669025f326c7fd3129952d768b1476ee6c
  dependency-type: direct:production
...

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

Author: dependabot[bot]