Change all Numba-dppy examples to work wih dpctl 0.7.0

[diptorupd]

Update all examples to use the latest dpctl 0.7.0 API pushed to main in #340.
Other improvements to examples.

[diptorupd]

There are few pending issues that need to be looked at:

• examples/blackscholes_njit.py segfaults when used with level zero.

[diptorupd]

@reazulhoque I investigated the examples/blackscholes_njit.py segfault and it might be an issue that already existed and is just getting caught by the changes I made to the example. The issue seems to be that either we are reusing the cached program that was compiled for OpenCL on level zero or we are passing an OpenCL allocated USM pointer to level zero and it is crashing inside DPC++. I do not know if there is anything we can do inside dpctl to prevent the crash, we need to get to the root cause before that.

[reazulhoque]

The issue in fact seems to be that we re relying on njit's caching mechanism which does not cascade down to the kernel level. So, we are reusing the njit function once we compile it even when the kernel that should be generated for the parfor regions are not the same.

[diptorupd]

The issue in fact seems to be that we re relying on njit's caching mechanism which does not cascade down to the kernel level. So, we are reusing the njit function once we compile it even when the kernel that should be generated for the parfor regions are not the same.

As discussed, I have changed the failing example and opened an issue ticket #343 to track the caching issue.