✨ Add remediation strategy support in MachineDeployment

[vincepri]

What this PR does / why we need it:

We're currently always remediating as much as the MachineHealthCheck marks as unhealthy without any waiting. This PR is a first step to fix that issue by adding a Remediation strategy on MachineDeployment which allows to set maxInFlight remediations allowed.

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

/area machineset

[vincepri]

/hold

[enxebre]

it'd be good to have test case that ensures max inflight is honoured, lgtm otherwise

[vincepri]

/hold cancel

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: 93e93d79444e789873f6a8ec02bd4ed8ca52c7ea

[vincepri]

/assign @sbueringer

for final review

[sbueringer]

Getting close, I think

[sbueringer]

/test pull-cluster-api-e2e-main

Thank you very much!

/lgtm

@fabriziopandini fyi, the new field is also supported in CC (see: #10712 (comment))

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: a8c9362ae8df69e2124741eef69e4e04a01fca54

[sbueringer]

/assign @fabriziopandini @chrischdi @enxebre
for a final pass

[fabriziopandini]

Great work!
/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: fabriziopandini

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[vincepri]

/cherry-pick release-1.7

[k8s-infra-cherrypick-robot]

@vincepri: #10712 failed to apply on top of branch "release-1.7":

Applying: sparkles: Add remediation strategy support for MachineSet
Using index info to reconstruct a base tree...
M	api/v1beta1/zz_generated.openapi.go
M	config/crd/bases/cluster.x-k8s.io_clusterclasses.yaml
M	config/crd/bases/cluster.x-k8s.io_clusters.yaml
M	config/crd/bases/cluster.x-k8s.io_machinedeployments.yaml
M	internal/apis/core/v1alpha3/zz_generated.conversion.go
M	internal/apis/core/v1alpha4/zz_generated.conversion.go
M	internal/controllers/machineset/machineset_controller.go
M	internal/controllers/machineset/machineset_controller_test.go
M	internal/webhooks/machinedeployment.go
M	test/e2e/clusterclass_rollout.go
Falling back to patching base and 3-way merge...
Auto-merging test/e2e/clusterclass_rollout.go
Auto-merging internal/webhooks/machinedeployment.go
Auto-merging internal/controllers/machineset/machineset_controller_test.go
Auto-merging internal/controllers/machineset/machineset_controller.go
CONFLICT (content): Merge conflict in internal/controllers/machineset/machineset_controller.go
Auto-merging internal/apis/core/v1alpha4/zz_generated.conversion.go
Auto-merging internal/apis/core/v1alpha3/zz_generated.conversion.go
Auto-merging config/crd/bases/cluster.x-k8s.io_machinedeployments.yaml
Auto-merging config/crd/bases/cluster.x-k8s.io_clusters.yaml
Auto-merging config/crd/bases/cluster.x-k8s.io_clusterclasses.yaml
Auto-merging api/v1beta1/zz_generated.openapi.go
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 sparkles: Add remediation strategy support for MachineSet
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".

In response to this:

/cherry-pick release-1.7

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