chore(release): 1.2.0 [skip ci]

# [1.2.0](https://git.gitlab.arm.com/bazel/toolchain_utils/compare/v1.1.0...v1.2.0) (2025-02-18)

### Features

* add `cygwin` C library constraint ([fea66a1a](https://git.gitlab.arm.com/bazel/toolchain_utils/commit/fea66a1ad5f6ce28f41e1c8d1338dc3658dbb0ac))
* export `TOOLCHAIN_{COU,TRI}PLETS` ([2a2baae8](https://git.gitlab.arm.com/bazel/toolchain_utils/commit/2a2baae88ca5b98ef255f89e58eb8020cb202832))