Rollup merge of #75179 - lzutao:unsed-ipv4-frominner, r=alexcrichton
Rollup merge of #75179 - lzutao:unsed-ipv4-frominner, r=alexcrichton

Remove unused FromInner impl for Ipv4Addr

The removed is a unused unstable implementation.

aidancully/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust,graydon/rust,graydon/rust