Add emit and machinelearning python envs

[rwegener2]

What has been built?

This PR adds to additional python kernels to the environment: machinelearning and lpdaac_emit

How was it done?

• cli commands were added to the postBuild script

How can it be tested?

• two new envs machinelearning and lpdaac_emit should appear as kernels in the Launcher
• import tensorflow should work from the machinelearning kernel
• import spectral should work from the lpdaac_emit kernel

[github-actions]

👈 Test this PR on Binder