feat: dry-run's client/server/none options with backwards compat

[colindean]

kubectl allows options [client|server|none] instead of just a boolean, starting at some version I'm not sure of. This enables that behavior with a fallback to if the user has passed true or false so folks don't need to update their configurations.

I've mapped true->client and false->none but otherwise treating the parameter as a string.

This is the warning seen when running plugin v0.3.0:

W1221 21:38:34.228830      22 helpers.go:653] --dry-run=false is deprecated (boolean value) and can be replaced with --dry-run=none.

[codecov]

Codecov Report

Merging #139 (082ec5a) into main (e22275c) will increase coverage by 0.38%.
The diff coverage is 90.00%.

@@            Coverage Diff             @@
##             main     #139      +/-   ##
==========================================
+ Coverage   60.00%   60.38%   +0.38%     
==========================================
  Files           9        9              
  Lines         615      621       +6     
==========================================
+ Hits          369      375       +6     
  Misses        244      244              
  Partials        2        2              

Impacted Files	Coverage Δ
cmd/vela-kubernetes/main.go	0.00% <0.00%> (ø)
cmd/vela-kubernetes/apply.go	98.46% <100.00%> (+0.15%)	⬆️

[colindean]

This getting kinda annoying the Vela logs:

WARNING: version difference between client (1.24) and server (1.21) exceeds the supported minor version skew of +/-1
$ /bin/kubectl --kubeconfig=/root/.kube/config apply --dry-run=false --filename=k8s/myproject/training_pvc.yaml
W0126 20:50:13.520375      22 helpers.go:653] --dry-run=false is deprecated (boolean value) and can be replaced with --dry-run=none.
persistentvolumeclaim/myteam--myproject--training--output unchanged
$ /bin/kubectl --kubeconfig=/root/.kube/config apply --dry-run=false --filename=k8s/anotherproject/training_pvc.yaml
W0126 20:50:14.763196      41 helpers.go:653] --dry-run=false is deprecated (boolean value) and can be replaced with --dry-run=none.
persistentvolumeclaim/myteam--anotherproject--training--output unchanged
$ /bin/kubectl --kubeconfig=/root/.kube/config apply --dry-run=false --filename=k8s/anotherproject/training_configmap.yaml
W0126 20:50:15.177479      59 helpers.go:653] --dry-run=false is deprecated (boolean value) and can be replaced with --dry-run=none.
configmap/myteam--anotherproject--training--config unchanged
$ /bin/kubectl --kubeconfig=/root/.kube/config apply --dry-run=false --filename=k8s/anotherproject/tag-and-deploy_configmap.yaml
W0126 20:50:15.588353      78 helpers.go:653] --dry-run=false is deprecated (boolean value) and can be replaced with --dry-run=none.
configmap/myteam--anotherproject--tag-and-deploy--config created

Can this PR get merged and released?

[plyr4]

hey @colindean sorry to review this so late, but it looks great to me, thank you

there are a couple tiny linter issues that can be resolved pretty easy so i left some suggestion comments.
once we get those i can approve :)

[plyr4]

lgtm, ty! :D