Fix pipeline

Due to an update of the docker containers, some parts of pystencils need to be adapted.

• The test test_field_layouts in test_buffer_gpu fails because the zeros function of a gpu_array can only deal with continuous data since 2021.1. Thus the test case fails now with the zyxf field layout. This was fixed by replacing zeros_like with empty_like
• matplotlib has dropped deprecated functionality. In particular, it is now necessary to distinguish between Axes3D and Axes. This was fixed by using Axes3D now.
• randomgen 1.20.0 changed the behavior of Philox's advance method. This was fixed by directly seeding to the correct counter value.
• kerncraft 0.8.10 made some internal changes which produces floats now. The problem was introduced in line 516 in this commit. In particular the determination of the counter variable is now different and produces floats instead of integers. This is probably a kerncraft bug because the loop counters should not be obtained as floats. Later in the code they enter a range function and this causes the failure.