Export of internal Abseil changes

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552959395a367b202e00fc7680e3500e4d15a341 by Abseil Team <absl-team@google.com>:

In span_test, correctly describe matches with negation, and remove redundant "is".

negation is true when the match is negative.

PiperOrigin-RevId: 267064695
GitOrigin-RevId: 552959395a367b202e00fc7680e3500e4d15a341
Change-Id: Ic876f30170e7e0008c13fdc6269462cfc5737e0f

absl/types/span_test.cc

@@ -35,7 +35,7 @@
 namespace {
 
 MATCHER_P(DataIs, data,
-          absl::StrCat("data() is ", negation ? "is " : "isn't ",
+          absl::StrCat("data() ", negation ? "isn't " : "is ",
                        testing::PrintToString(data))) {
   return arg.data() == data;
 }