gwcelery/tasks/inference.py: do not move to rapidpe directory

It seems changing the current directory during the rapidpe dag generation can change the current directory for other tasks. For example, the bilby submit file /home/emfollow-playground/.cache/bilby/S230316x/quick_bns/submit/G941909_data0_1362966969-4414847_generation.submit implies the submit file was generated from the rapidpe directory /home/emfollow-playground/.cache/rapidpe/S230316u. Since the bilby dag was then submitted from the home directory, it fails as follows:

/15/23 19:01:56 Read so far: ERROR: Failed to open command file (../../bilby/S230316x/quick_bns/submit/G941909_data0_1362966969-4414847_generation.submit) (No such file or directory)

So this MR remove lines to change the current directory during the rapidpe dag generation process. cc: @cody.messick