rpk: disable tune checkers in rp start unit test

[r-vasquez]

Cover letter

Small change to avoid running the tune checkers in the unit tests for rpk redpanda start. This will reduce unit test time by ~70%:

# From
go test ./... -count=1  11.36s user 2.66s system 18% cpu 1:17.14 total

# To
go test ./... -count=1  11.25s user 1.94s system 70% cpu 18.609 total

Why?

• It doesn't make much sense to run the checkers in a memory-backed filesystem (Afero.MemMapFs) during unit testing.
• We already have unit tests for checkers in rpk/pkg/tuners and tuner tests in ducktape: https://github.com/redpanda-data/redpanda/blob/dev/tests/rptest/tests/rpk_tuner_test.py
• 11 checkers always fail:

System check "Free memory per CPU [MB]" failed with non-fatal error "open /proc/self/cgroup: file does not exist"
System check "Transparent huge pages active" failed with non-fatal error "open /sys/kernel/mm/transparent_hugepage/enabled: file does not exist"
System check "Dir '/var/lib/redpanda/data' scheduler tuned" failed with non-fatal error "open /sys/devices/virtual/block/dm-1/uevent: file does not exist"
System check "Dir '/var/lib/redpanda/data' nomerges tuned" failed with non-fatal error "open /sys/devices/virtual/block/dm-1/uevent: file does not exist"
System check "Dir '/var/lib/redpanda/data' IRQs affinity static" failed with non-fatal error "open /sys/devices/virtual/block/dm-1/uevent: file does not exist"
System check "Dir '/var/lib/redpanda/data' IRQs affinity set" failed with non-fatal error "open /sys/devices/virtual/block/dm-1/uevent: file does not exist"
System check "Connections listen backlog size" failed with non-fatal error "open /proc/sys/net/core/somaxconn: file does not exist"
System check "Max syn backlog size" failed with non-fatal error "open /proc/sys/net/ipv4/tcp_max_syn_backlog: file does not exist"
System check "Max AIO Events" failed with non-fatal error "open /proc/sys/fs/aio-max-nr: file does not exist"
System check "Clock Source" failed with non-fatal error "open /sys/devices/system/clocksource/clocksource0/current_clocksource: file does not exist"
System check "Swappiness" failed with non-fatal error "open /proc/sys/vm/swappiness: file does not exist"

Backport Required

• not a bug fix

UX changes

• none

Release notes

• none

[r-vasquez]

Failure in https://buildkite.com/redpanda/redpanda/builds/13285#018246c2-3e95-44dc-87db-0cdce324c494
Is: #5711