follow-up: removal of the ratelimit ir

[shawnh2]

What type of PR is this?

this PR will remove all logic related to ratelimit ir.

What this PR does / why we need it:

we don't need it anymore since the ratelimit have been switched to XDS mode, and the ratelimit can be created by config statically.

Which issue(s) this PR fixes:

related to #1416

[codecov]

Codecov Report

Merging #1451 (b5860f8) into main (1fb3d51) will decrease coverage by 0.01%.
The diff coverage is 45.45%.

@@            Coverage Diff             @@
##             main    #1451      +/-   ##
==========================================
- Coverage   61.48%   61.48%   -0.01%     
==========================================
  Files          79       79              
  Lines       11439    11410      -29     
==========================================
- Hits         7033     7015      -18     
+ Misses       3945     3932      -13     
- Partials      461      463       +2     

Impacted Files	Coverage Δ
internal/cmd/server.go	16.66% <0.00%> (+0.91%)	⬆️
internal/ir/zz_generated.deepcopy.go	12.97% <ø> (+0.29%)	⬆️
internal/message/types.go	0.00% <ø> (ø)
...tructure/kubernetes/ratelimit/resource_provider.go	95.83% <100.00%> (-0.05%)	⬇️
...ernal/infrastructure/kubernetes/ratelimit_infra.go	50.00% <100.00%> (-16.67%)	⬇️

... and 2 files with indirect coverage changes

[qicz]

LGTM

[arkodg]

LGTM, thanks for the clean up

[qicz]

lgtm