Remove / update old notes & remove some old skipped tests

[fselmo]

What was wrong?

• Remove note about ENSIP-15 breaking changes from v6
• Remove old, un-tested uncles tests as they are no longer a thing after switch to PoS.
• Change TODO note on breaking changes from v7 -> v8

Todo:

• Clean up commit history
• Add or update documentation related to these changes
• Add entry to the release notes

Cute Animal Picture

courtesy of gpt o3-mini-high 🤔

       .-=========-.
       |  IRISH    |
       |  DOODLE   |
       '-----------'
            ||
         .-'''''-.
       .'  .-. .-.  '.
      /   ( o ) ( o )  \
     |     '-'   '-'    |
     |  \             / |
      \  '.         .'  /
       '.  `'-----'`  .'
         '-._______.-'
           |     |
         __|     |__
        /  |     |  \
       /   |     |   \
      /____|_____|____\
         (_________)

[fselmo]

Chore PR to remove some old things. Follow-up q, should we deprecate eth_getUncle* endpoints / methods to be removed in v8? Could add that in here as well while eyes are there.

[pacrob]

Chore PR to remove some old things. Follow-up q, should we deprecate eth_getUncle* endpoints / methods to be removed in v8? Could add that in here as well while eyes are there.

makes sense to me