mathlib

23b80727 - chore(analysis/inner_product_space/symmetric): change lemma name (#18777)

chore(analysis/inner_product_space/symmetric): change lemma name (#18777) changed name from [`linear_map.is_symmetric.inner_map_eq_zero`](https://leanprover-community.github.io/mathlib_docs/analysis/inner_product_space/symmetric.html#linear_map.is_symmetric.inner_map_eq_zero) to `linear_map.is_symmetric.inner_map_self_eq_zero` to match [`inner_map_self_eq_zero`](https://leanprover-community.github.io/mathlib_docs/analysis/inner_product_space/basic.html#inner_map_self_eq_zero)