docs: Use ConfigMap to disable TLS

[renaudguerin]

This updates the Ingress section of the operator manual to suggest the use of the easier argocd-cmd-params-cm ConfigMap method in order to disable TLS in argocd-server, rather than editing the Deployment directly.

• [X] Either (a) I've created an enhancement proposal and discussed it with the community, (b) this is a bug fix, or (c) this does not need to be in the release notes.
• [X] The title of the PR states what changed and the related issues number (used for the release note).
• [X] I've updated documentation as required by this PR.
• [X] I have signed off all my commits as required by DCO
• [X] My build is green (troubleshooting builds).

[codecov[bot]]

Codecov Report

Merging #10106 (dc7430d) into master (44fea52) will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##           master   #10106   +/-   ##
=======================================
  Coverage   45.87%   45.87%           
=======================================
  Files         227      227           
  Lines       27373    27373           
=======================================
  Hits        12556    12556           
  Misses      13113    13113           
  Partials     1704     1704           

Impacted Files	Coverage Δ
util/settings/settings.go	50.90% <0.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 44fea52...dc7430d. Read the comment docs.

[crenshaw-dev]

Cherry-picked onto release-2.4 for 2.4.9.