remove IPVS module drop-in for kubelet

[bcressey]

Issue number:
N/A

Description of changes:
Essentially reverts 7919d89.

We added the proactive load of IPVS modules to allow kube-proxy to use the functionality even though its older kmod version couldn't handle zstd-compressed modules.

However, the zstd-compressed modules change was subsequently reverted because of widespread compatibility issues. So the proactive load is no longer necessary, and slightly delays kubelet start.

Testing done:
Put the kube-proxy EKS managed add-on into IPVS mode and verified that the scheduler kmods were automatically loaded.

{
	"mode": "ipvs",
	"ipvs": {
		"scheduler": "lc"
	}
}

[   25.697354] IPVS: Registered protocols (TCP, UDP, SCTP, AH, ESP)
[   25.697371] IPVS: Connection hash table configured (size=4096, memory=32Kbytes)
[   25.697413] IPVS: ipvs loaded.
[   25.702272] IPVS: [lc] scheduler registered

{
	"mode": "ipvs",
	"ipvs": {
		"scheduler": "wrr"
	}
}

[   18.671353] IPVS: Registered protocols (TCP, UDP, SCTP, AH, ESP)
[   18.671372] IPVS: Connection hash table configured (size=4096, memory=32Kbytes)
[   18.671415] IPVS: ipvs loaded.
[   18.676638] IPVS: [wrr] scheduler registered.

Terms of contribution:

By submitting this pull request, I agree that this contribution is dual-licensed under the terms of both the Apache License, version 2.0, and the MIT license.