The API catalog endpoint `show_categories` was deprecated back
in Liberty cycle. It was recently removed from murano in
If1bea7448c0d4aa5fdf37c8400323589d73fdb21
This commit removes the muranoclient usage of this now-removed
endpoint, which is currently used by muranodashboard, causing
bugs. There is a commit for muranodashboard to address this
problem: I715b1c9ccfdd044980596cc6d966062e0386884c
After muranodashboard stops referencing the deprecated
endpoint in favor of the current one, all references
to the deprecated endpoint will have been removed.
Related change: If1bea7448c0d4aa5fdf37c8400323589d73fdb21
Change-Id: I2024fc1e5705f581579ecabaec30f66687a272d7
Depends-On: I715b1c9ccfdd044980596cc6d966062e0386884c
Partial-Bug: #1701067