Decide which kernels to submit outside of handler functions in in gemm

[oleksandr-pavlyk]

Moved logic of submitting different kernels in gemm outside of handler function

This should improve debugging experience, where one can see in the debugger which branch the execution took.

No other logic has been changed.

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[github-actions]

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

[coveralls]

coverage: 91.065%. remained the same
when pulling f7188ce on minimize-branching-in-handler-function
into 89266a7 on master.

[github-actions]

Array API standard conformance tests for dpctl=0.15.1dev3=py310h15de555_71 ran successfully.
Passed: 909
Failed: 0
Skipped: 86

[ndgrigorian]

LGTM!