Remove the legacy ui Helm component from TACC's deployment #81

Question

Graduated from the map's fog by #69.

The production upgrade in #77 moves mint.tacc.utexas.edu onto ui-react and leaves the
legacy ui (mint-ui-lit) Helm component deployed but unrouted — the only undo available
if the client hits something during sign-off. Once #80 has the client's sign-off, that hedge
has expired.

Remove the ui component from TACC's Helm values and apply. Confirm nothing else in the chart
references it.

This is the last thing on the map that touches TACC's cluster; it does not gate sign-off, it
follows it.