[lldb] Building the documentation should not depend on libLLDB (#168962)

The only thing the docs should depend on is on the SWIG wrapper
(lldb.py) which only requires parsing the API headers. It should not
depend on building libLLDB.

The dependency was (I believe accidentally) introduced by 59f4267.

Fixes #123316

Author: JDevlieghere

lldb/docs/CMakeLists.txt

@@ -34,7 +34,7 @@ if (LLDB_ENABLE_PYTHON AND SPHINX_FOUND)
       COMMAND "${CMAKE_COMMAND}" -E copy "${LLDB_SOURCE_DIR}/examples/python/templates/scripted_thread_plan.py" "${CMAKE_CURRENT_BINARY_DIR}/lldb/plugins/"
       COMMENT "Copying lldb.py to pretend its a Python package.")
 
-    add_dependencies(lldb-python-doc-package swig_wrapper_python lldb-python)
+    add_dependencies(lldb-python-doc-package swig_wrapper_python)
 
     # FIXME: Don't treat Sphinx warnings as errors. The files generated by
     # automodapi are full of warnings (partly caused by SWIG, our documentation