[Chapel Merge] Fix memory leak with const check warning message

Branch: refs/heads/main
Revision: 50e0287a676f52e80fb64cc4b2e9901f9157d49a
Author: lydia-duncan
Link: Fix memory leak with const check warning message by lydia-duncan · Pull Request #23968 · chapel-lang/chapel · GitHub
Log Message:
Fix memory leak with const check warning message (#23968)

[reviewed by @mppf]

chpl_glom_strings allocates memory for the message, so we need to clean
it up when we are done with it.

Checked the new tests with -memLeaks and the remote test with
CHPL_COMM=gasnet and -memLeaks

Compare: Comparing e547028a5e9088b012e95c4fc631aa8590c1a711...f55a60eb0a3011e22ee43c8fd0f6e7ae751f2760 · chapel-lang/chapel · GitHub

Diff:
M runtime/src/chpl-const-arg-check.c
https://github.com/chapel-lang/chapel/pull/23968.diff