gmock-spec-builders: remove the name for an unused parameter.
gmock-spec-builders: remove the name for an unused parameter.

This fixes unused parameter errors under both MSVC and clang (when
`-Werror=unused-parameter` is used, as reported
[here](https://github.com/google/googletest/commit/9d21db9e0a60a1ea61ec19331c9bc0dd33e907b1#r74769946)).

Fixes #3858

PiperOrigin-RevId: 451907906
Change-Id: Ic07da19ea6a547eb1797fbbab19cd57cc2a83fe8

google/googletest,google/googletest,google/googletest,google/googletest