[v26.1.x] CORE-15586 Config: Suppress changes to needs_restart properties until restart.

[vbotbuildovich]

Backport #30109 to branch v26.1.x. This issue was created as a placeholder because the original PR's commit(s) could not be automatically cherry-picked.
Here are the commands to execute:

git checkout v26.1.x
git checkout -b manual-backport-30109-v26.1.x-155
git cherry-pick -x d62e23215f fb13916211 ebd511a772 89ae3edbd0 5071dc4e71 3d1255a7fc d70c1c15af

git push origin manual-backport-30109-v26.1.x-155
gh pr create \
  --title "[v26.1.x] CORE-15586 Config: Suppress changes to needs_restart properties until restart." \
  --base "v26.1.x" \
  --label "kind/backport" \
  --head "manual-backport-30109-v26.1.x-155" \
  --draft \
  --repo "redpanda-data/redpanda" \
  --milestone "v26.1.x-next" \
  --body "Backport of PR https://github.com/redpanda-data/redpanda/pull/30109 "