Clean up the CNI CRS which is done via generators

[jsturtevant]

What type of PR is this?
/kind bug
/kind cleanup
/kind failing-test

What this PR does / why we need it:
#1333 moved all the cni configuration for CI to kustomize generators. This left out kube-proxy for Windows with caused failures in the tests in #1119.

The code that was configuring the CNI during the e2e suite is no longer required as well.

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 #

Special notes for your reviewer:

Please confirm that if this PR changes any image versions, then that's the sole change this PR makes.

TODOs:

• squashed commits
• includes documentation
• adds unit tests

Release note:

NONE

/assign @chewong @CecileRobertMichon

[nader-ziada]

/lgtm
/approve

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[CecileRobertMichon]

looks like https://testgrid.k8s.io/sig-cluster-lifecycle-cluster-api-provider-azure#capz-periodic-capi-e2e-main is failing since this merged with:

    Unexpected error:
        <*yamlprocessor.errMissingVariables | 0xc001048000>: {
            Missing: ["CNI_RESOURCES"],
        }
        value for variables [CNI_RESOURCES] is not set. Please set the value using os environment variables or the clusterctl config file
    occurred
    ```
    
We need to either re-add the CNI_RESOURCES variables, or add CNIs to the templates in https://github.com/kubernetes-sigs/cluster-api-provider-azure/blob/master/test/e2e/data/infrastructure-azure