doc: Fix unclosed command formatting

Currently there is an unclosed backtick (`) which shows the following
error while building the documentation:

sources\pyside6\doc\building_from_source/macOS.rst:77: WARNING: Inline
interpreted text or phrase reference start-string without end-string.

This patch fixes the issue.

Pick-to: 6.9
Change-Id: I37ae34ca12e249e219ae765f121ee2f1bb2d371c
Reviewed-by: Cristian Maureira-Fredes <[email protected]>

Author: Jaime Resano

sources/pyside6/doc/building_from_source/macOS.rst

@@ -74,7 +74,7 @@ For building the documentation::
 
 .. note:: Keep in mind you need to use the same version as your Qt installation
 
-.. note:: With `uv`_, use `uv pip install ...
+.. note:: With `uv`_, use ``uv pip install ...``
 
 Building PySide
 ~~~~~~~~~~~~~~~