detect/ssh: remove deprecated keywords

[catenacyber]

Link to ticket: https://redmine.openinfosecfoundation.org/issues/
https://redmine.openinfosecfoundation.org/issues/2377

Found via https://suricata.io/our-story/deprecation-policy/

Describe changes:

• detect/ssh: remove deprecated keywords

SV_BRANCH=OISF/suricata-verify#1928

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 82.39%. Comparing base (6256391) to head (7dfd7c6).

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #11332      +/-   ##
==========================================
- Coverage   82.41%   82.39%   -0.03%     
==========================================
  Files         934      931       -3     
  Lines      247239   246682     -557     
==========================================
- Hits       203773   203251     -522     
+ Misses      43466    43431      -35     

Flag	Coverage Δ
fuzzcorpus	60.22% <ø> (-0.03%)	⬇️
livemode	18.75% <ø> (+<0.01%)	⬆️
pcap	43.66% <ø> (-0.14%)	⬇️
suricata-verify	61.36% <ø> (+0.01%)	⬆️
unittests	59.25% <ø> (-0.06%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

[suricata-qa]

Information: QA ran without warnings.

Pipeline 21150

[catenacyber]

I should also remove the documentation for these keywords...

[catenacyber]

Continued in #11448