Bump external/Catch2 from d4b0b34 to a7782d1

Bumps [external/Catch2](https://github.com/catchorg/Catch2) from `d4b0b34` to `a7782d1`.
- [Release notes](https://github.com/catchorg/Catch2/releases)
- [Commits](catchorg/Catch2@d4b0b34...a7782d1)

---
updated-dependencies:
- dependency-name: external/Catch2
  dependency-type: direct:production
...

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