Replace local TestSocketUtils with the one in spring-test

[onobc]

Once spring-projects/spring-framework#28210 adds TestSocketUtils we should remove the temporary ones recently added:

• 1fb5af2#diff-22f02a66dd8b5e32b8fe149c40d0c139659f57b1fcb946386c94d8adcde1f613R30
• 1fb5af2#diff-d37cfba905a637b0311a0840e5dfb20585d453fe855beae5cdaf41fce978df5bR30

[olegz]

As discussed, we can also remove SocketUtils that I just created inside of SCF

[olegz]

Chris, should we close it? If I remember correctly we discussed that it will be addressed with your Azure custom runtime commit

[onobc]

No this is still waiting on the change in the framework. Once its available I will get it in here.

I think you are thinking that I would remove the public one that was added in previous commits (in the scope of my PR - which I have not gotten to yet but will shortly).