ci: Update CNS daemonset capabilities within E2E

[jpayne3506]

Reason for Change:

Updates CNS daemonset capabilities to ensure that a race condition does not occur when creating the /var/run/azure-vnet directory

Issue Fixed:

Contributes to CI/CD to cover #2818

Requirements:

• uses conventional commit messages
• includes documentation
• adds unit tests
• relevant PR labels added

Notes:

[timraymond]

This looks fine to me, but I'm a little unclear as to how dropping capabilities prevents a race condition on creating a directory. Can you explain in a comment before you merge?

[rbtr]

It is not preventing a race, it is testing that we no longer have a race between the CNI and kubelet creating the dirs with incompatible permissions. CNI used to make it with 0644, but kubelet would make it with 0755 - so if CNI wins, CNS should not have access to the dir.
...but it does, because it has CAP_DAC_OVERRIDE by default. Dropping caps exposes the race and ensures we have resolved it by changing the CNI Mkdir perms.
This was a fun one to debug 🥲

[rbtr]

fixes #2818

[timraymond]

@rbtr Awesome, that makes sense to me :)

[jpayne3506]

Thanks for the explanation @rbtr, was going to link the issue and ask for you to comment more if needed 😆 .