[Chapel Merge] CHANGES.md updates for Chapel 2.7

Branch: refs/heads/main
Revision: 2c63b2d30f6fcfa68c8968934c5fc6d363020f86
Author: bradcray
Link: CHANGES.md updates for Chapel 2.7 by bradcray · Pull Request #28140 · chapel-lang/chapel · GitHub
Log Message:
CHANGES.md updates for Chapel 2.7 (#28140)

[reviewed by @DanilaFe and @lydia-duncan]

Thanks to everyone for their hard work improving Chapel for 2.7!

Compare: Comparing 4fc96e5c0e5b00786a9e2d040ab990461cbbae3c...3f92c02e0505491197e5d77326d26a18a675da3e · chapel-lang/chapel · GitHub

Diff:
M CHANGES.md
https://github.com/chapel-lang/chapel/pull/28140.diff