feat: disable expression routes mode when ExpressionRoutes is on but CombinedRoutes is off

[randmonkey]

What this PR does / why we need it:

Since we did not implement the translator for ingresses and httproutes to expression based routes, we disable expression routes mode of parser when ExpressionRoutes is enabled but CombinedRoutes is disabled.

Which issue this PR fixes:

fixes #4043

Special notes for your reviewer:

PR Readiness Checklist:

Complete these before marking the PR as ready to review:

• the CHANGELOG.md release notes have been updated to reflect any significant (and particularly user-facing) changes introduced by this PR

[codecov]

Codecov Report

Patch coverage: 100.0% and project coverage change: +0.1 🎉

Comparison is base (5d29975) 59.8% compared to head (4b0aa51) 59.9%.

❗ Current head 4b0aa51 differs from pull request most recent head c9af630. Consider uploading reports for the commit c9af630 to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #4057     +/-   ##
=======================================
+ Coverage   59.8%   59.9%   +0.1%     
=======================================
  Files        149     149             
  Lines      16482   16491      +9     
=======================================
+ Hits        9862    9892     +30     
+ Misses      5988    5971     -17     
+ Partials     632     628      -4     

Impacted Files	Coverage Δ
internal/dataplane/parser/parser.go	75.9% <100.0%> (+1.1%)	⬆️

... and 2 files with indirect coverage changes

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