ci: add dl.k8s.io to egress policy allowlist for toolchain

[comtalyst]

Fixes #

Description This is being used in toolchain (for 1.25 CI pipeline only). Need to add it to allow list.

How was this change tested?

• CI

Does this change impact docs?

• [ ] Yes, PR includes docs updates
• [ ] Yes, issue opened: #
• [X] No

Release Note

NONE

[coveralls]

Pull Request Test Coverage Report for Build 11413562865

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 97.866%

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Totals
Change from base Build 11398977564:	0.0%
Covered Lines:	36318
Relevant Lines:	37110

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💛 - Coveralls