[release-1.29] test: don't return error when deleting rg failed in sanity test

[andyzhangx]

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

What this PR does / why we need it:
test: don't return error when deleting rg failed in sanity test

cherrypick of #2071

Which issue(s) this PR fixes:

Fixes #

Requirements:

• uses conventional commit messages
• includes documentation
• adds unit tests
• tested upgrade from previous version

Special notes for your reviewer:

Release note:

none

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: andyzhangx

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[k8s-ci-robot]

@andyzhangx: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
pull-azurefile-csi-driver-sanity	2d62a17	link	true	/test pull-azurefile-csi-driver-sanity

Full PR test history. Your PR dashboard. Please help us cut down on flakes by linking to an open issue when you hit one in your PR.

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