build(deps): bump third_party/yaml-cpp from `d7f672d` to `987a604` (#2121)

Bumps [third_party/yaml-cpp](https://github.com/jbeder/yaml-cpp) from `d7f672d` to `987a604`.
- [Release notes](https://github.com/jbeder/yaml-cpp/releases)
- [Commits](https://github.com/jbeder/yaml-cpp/compare/d7f672d1413040d2ea850ecb32644150da2e10db...987a60425611bfd02a90bd247d630483bceaaeee)

---
updated-dependencies:
- dependency-name: third_party/yaml-cpp
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
diff --git a/third_party/yaml-cpp b/third_party/yaml-cpp
index d7f672d..987a604 160000
--- a/third_party/yaml-cpp
+++ b/third_party/yaml-cpp
@@ -1 +1 @@
-Subproject commit d7f672d1413040d2ea850ecb32644150da2e10db
+Subproject commit 987a60425611bfd02a90bd247d630483bceaaeee