Clarify the TESTFN argument to `alist-get'
* lisp/subr.el (alist-get): Rephrase the initial text to clarify the meaning of the TESTFN argument. It's an equality predicate, not a look-up function (Bug#35206). (cherry picked from commit c8146558)
* lisp/subr.el (alist-get): Rephrase the initial text to clarify the meaning of the TESTFN argument. It's an equality predicate, not a look-up function (Bug#35206). (cherry picked from commit c8146558)