[lldb][docs] Added LLDB_ENFORCE_STRICT_TEST_REQUIREMENTS for macOS configuration (#130381)

Referenced here:
https://github.com/llvm/llvm-project/issues/130171#issuecomment-2707058235

I think this will allow for issues relating towards missing modules for
test suites to be more manageable.

cc @adrian-prantl

---------

Co-authored-by: medievalghoul <61852278+medievalghoul@users.noreply.github.com>

lldb/docs/resources/build.rst

diff --git a/lldb/docs/resources/build.rst b/lldb/docs/resources/build.rst
index 214c5f6..9ba2405 100644
--- a/lldb/docs/resources/build.rst
+++ b/lldb/docs/resources/build.rst
@@ -340,7 +340,7 @@
   code-signed with identity ``lldb_codesign`` (see :ref:`CodeSigning`).
 * ``LLDB_USE_SYSTEM_DEBUGSERVER:BOOL``: Use the system's debugserver, so lldb is
   functional without setting up code-signing.
-
+* ``LLDB_ENFORCE_STRICT_TEST_REQUIREMENTS:BOOL``: Detect missing packages or modules at configuration time.
 
 .. _CMakeCaches: