Improve Docker image of rocm flashinfer published at https://hub.docker.com/r/rocm/flashinfer

[diptorupd]

The current docker image has two design issues:

a) The sources are part of the image and can potentially lead to issues if a user of the image changes directory and gets in the source directory. The sources should be removed from the published image as it is primarily meant for end users.

b) The amd-flashinfer wheel package is installed in a custom micromamba env requiring end users to first switch to the right env. Ideally, the package should be installed in the base image.

[demandal25]

@diptorupd Can you please confirm if this is already addressed and can be closed now?

[diptorupd]

Completed as part of releases v0.5.3+amd.1 and v0.5.3+amd.2