Bump EKS-A CLI Homebrew version to latest

[sp1999]

Issue #, if available:
#2402

Description of changes:
Bump EKS-A CLI Homebrew version to latest v0.21.0.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[sp1999]

/approve

[sp1999]

/cherry-pick release-0.21

[eks-distro-pr-bot]

@sp1999: once the present PR merges, I will cherry-pick it on top of release-0.21 in a new PR and assign it to you.

In response to this:

/cherry-pick release-0.21

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[panktishah26]

/lgtm
/approve

[eks-distro-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: panktishah26, sp1999

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• OWNERS [panktishah26,sp1999]

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[jhaanvi5]

/lgtm

[eks-distro-pr-bot]

@sp1999: #8949 failed to apply on top of branch "release-0.21":

Applying: Bump EKS-A CLI Homebrew version to latest
Using index info to reconstruct a base tree...
M	release/triggers/brew-version-release/CLI_RELEASE_VERSION
Falling back to patching base and 3-way merge...
Auto-merging release/triggers/brew-version-release/CLI_RELEASE_VERSION
CONFLICT (content): Merge conflict in release/triggers/brew-version-release/CLI_RELEASE_VERSION
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 Bump EKS-A CLI Homebrew version to latest
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-0.21

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.