Bump external/Catch2 from `b56c474` to `ec59cd8` (#1576)

Bumps [external/Catch2](https://github.com/catchorg/Catch2) from `b56c474` to `ec59cd8`.
- [Release notes](https://github.com/catchorg/Catch2/releases)
- [Commits](b56c474260...ec59cd8736)

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

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external/Catch2

@@ -1 +1 @@
-Subproject commit b56c4742606c2926f5c9cc6ad2b4ce622b888918
+Subproject commit ec59cd8736b7ee8fcd69c76c71c2a0b72293b00c