fix(stock): hide expiration date on asset entry

[jniles]

This commit ensures that the expiration date is hidden on asset entry.

Closes #6588.

To test:

1. Create or update an asset in the inventory list.
2. Attempt a stock entry.
3. Note that the expiration date column in the "Lots" modal is not visible.
4. Attempt a stock entry with a regular lot.
5. Note that the column is now visible.

[jmcameron]

I looked over the code changes and they seem fine.
I tested it with Bhima_test and it works as described.

[jmcameron]

bors r+

[bors]

Build succeeded:

• ci/semaphoreci/push: Integration Tests