Remove private method lookup in dpctl_capi

[oleksandr-pavlyk]

This PR removes private method dpctl_capi::lookup.

This removes one of static dpctl_capi instance from dpctl_capi definition. This leaves a single static instance created dynamically in get static method.

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[github-actions]

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

[coveralls]

coverage: 87.832%. remained the same
when pulling 482bd55 on remove-extra-static-copy-of-dpctl-capi
into 116cb3b on master.

[github-actions]

Array API standard conformance tests for dpctl=0.17.0dev0=py310h15de555_136 ran successfully.
Passed: 906
Failed: 0
Skipped: 94