Recipes/OffloadSubConfigMixin.py: remove gro offload config check

[jtluka]

Description

Resolves #300

Since kernel 5.10 GRO is enabled for UDP: https://developers.redhat.com/articles/2021/11/05/improve-udp-performance-rhel-85#benchmarking_gro

Tests

Tested with following test configuration:

recipe = SimpleNetworkRecipe(                                                   
    ping_count=1,                                                               
    perf_duration=5,                                                            
    perf_iterations=1,                                                          
    perf_parallel_processes=1,                                                  
    perf_tests=['udp_stream'],                                                  
    ip_versions=['ipv4'],                                                       
    perf_msg_sizes=[16384],                                                     
    offload_combinations=[{'gro': 'off'}],                                      

• master branch: no iperf test was run
• this devel branch: iperf test was run

Reviews

Closes: #300

[olichtne]

we still run tests on rhel8 which is version 4.18 so i guess we'll have to be careful to avoid those configurations yes?

[jtluka]

The FunctionalTest fail is expected and known issue of urllib3 in pypi fetched by poetry.

The tests I did should be sufficient to cover that scenario.