Remove remaining anonymous namespaces from headers

[ndgrigorian]

This PR proposes removing two anonymous namespaces from headers

This will reduce possible binary size bloating, and prevents potential undefined behavior

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[github-actions]

Deleted rendered PR docs from intelpython.github.com/dpctl, latest should be updated shortly. 🤞

[coveralls]

coverage: 85.897% (-0.01%) from 85.908%
when pulling 30b35ba on remove-anonymous-namespaces-from-headers
into c76f67e on master.

[github-actions]

Array API standard conformance tests for dpctl=0.21.0dev0=py310h93fe807_101 ran successfully.
Passed: 1114
Failed: 7
Skipped: 119