[Tooling] Remove use of -compat flag for go mod

[marckhouzam]

What this PR does / why we need it

Stop using the go mod -compat flag which was only useful when using Go 1.17.

When we were using go 1.17, we decided to use the -compat=1.17 flag of go mod so as to use the pruned Go module graph introduced by Go 1.17. Details can be found in this Stack Overflow answer and in the Go documentation.

Now that we are running Go 1.18 thanks to #3577, go mod will build the dependency graph for go 1.18 and 1.17, which both use the pruned graph.

We therefore don't need to use the -compat=1.17 flag anymore.

Which issue(s) this PR fixes

Fixes #3569

Describe testing done for PR

Make sure to be running Go 1.18.
Apply this PR and run make modules and see that no files are changed.

[marckhouzam]

We're going to hold on this as the change to Go 1.18 may be reverted by #3571

[vuil]

lgtm, thanks!

[marckhouzam]

Now that #3577 has been merged, we should go ahead and do this cleanup.

[codecov]

Codecov Report

Merging #3570 (6ef7f9c) into main (83f9375) will decrease coverage by 0.87%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #3570      +/-   ##
==========================================
- Coverage   46.31%   45.44%   -0.88%     
==========================================
  Files         400      425      +25     
  Lines       39583    41147    +1564     
==========================================
+ Hits        18334    18698     +364     
- Misses      19563    20747    +1184     
- Partials     1686     1702      +16     

Impacted Files	Coverage Δ
cmd/cli/plugin/cluster/machinehealthcheck.go	100.00% <0.00%> (ø)
cmd/cli/plugin/cluster/kubeconfig_get.go	8.82% <0.00%> (ø)
...in/cluster/set_machinehealthcheck_control_plane.go	21.21% <0.00%> (ø)
...i/plugin/cluster/delete_machinehealthcheck_node.go	16.66% <0.00%> (ø)
cmd/cli/plugin/cluster/credentials_update.go	9.23% <0.00%> (ø)
...in/cluster/get_machinehealthcheck_control_plane.go	11.11% <0.00%> (ø)
cmd/cli/plugin/cluster/main.go	0.00% <0.00%> (ø)
cmd/cli/plugin/cluster/scale.go	17.85% <0.00%> (ø)
.../cli/plugin/cluster/get_machinehealthcheck_node.go	9.30% <0.00%> (ø)
.../cli/plugin/cluster/set_machinehealthcheck_node.go	23.33% <0.00%> (ø)
... and 16 more

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