Drop OUTPUT_PYTHON from 0:UART

[fornellas]

I'm not sure the rationale, but we have 2 UART decoders:

• 0:UART says it outputs uart, documents it at OUTPUT_PYTHON but does NOT output anything.
  • This means that stacked decoders receive nothing.
• 1:UART says it outputs uart, documents it at OUTPUT_PYTHON and DOES output it.

This PR removes the wrong declaration from 0:UART so that people cant't attempt to stack decodes for the case where it does not work.

PS: I've cut a PR to add upstream uart decoder which does not have the issue above and supports setting RX & TX #429. Perhaps the fix here is simply removing both problematic 0:UART and 1:UART.

[fornellas]

@dreamsource-tai why was this PR closed? I believe this problem still exists on master.

[fornellas]

@dreamsource-tai any reason why this PR can't be merged? It's been open for over a year at this point...

[fornellas]

@dreamsource-tai any reason why this PR can't be merged? It's been open for over a year at this point. It should be either merged or rejected with a reason why.

PS: perhaps the solution could be simply to remove both broken UART decoders, see discussion here.

[DreamSourceLab]

@fornellas
In the software manual, we have pointed out the limitations of decoders starting with 0:

Your PR is right, we should remove the ourput declaration from 0:UART.