Remove calling commit_with_diff from generate_new_block_and_state

Usage related changes

additional test for remove of self.commit_with_diff is not needed sinceblocks_on_demand_states_and_blocks() test is checking that scenario

[x] Checked out the contribution guidelines
[x] Applied formatting - ./scripts/format.sh
[x] No linter errors - ./scripts/clippy_check.sh
[x] No unused dependencies - ./scripts/check_unused_deps.sh
[x] No spelling errors - ./scripts/check_spelling.sh
[x] Performed code self-review
[x] Rebased to the latest commit of the target branch (or merged it into my branch)
[x] Updated the docs if needed - ./website/README.md
[x] Linked the issues resolvable by this PR - linking info
[x] Updated the tests if needed; all passing - execution info