find_*: support suppressing implicit transition events

When projects explicitly unset variables, the transition detection can
end up reporting events when they are not desired.

See: #24833

Help/variable/CMAKE_FIND_DEBUG_MODE_NO_IMPLICIT_CONFIGURE_LOG.rst

@@ -0,0 +1,26 @@
+CMAKE_FIND_DEBUG_MODE_NO_IMPLICIT_CONFIGURE_LOG
+-----------------------------------------------
+
+.. versionadded:: 4.1
+
+The following commands will report configure log events when they experience a
+transition between found and not-found states or when the result is first
+defined:
+
+* :command:`find_program`
+* :command:`find_library`
+* :command:`find_file`
+* :command:`find_path`
+* :command:`find_package`
+
+The ``CMAKE_FIND_DEBUG_MODE_NO_IMPLICIT_CONFIGURE_LOG`` boolean variable
+suppresses these implicit events from the configure log when set to a true
+value.
+
+.. code-block:: cmake
+
+  set(CMAKE_FIND_DEBUG_MODE_NO_IMPLICIT_CONFIGURE_LOG TRUE)
+  find_program(...)
+  set(CMAKE_FIND_DEBUG_MODE_NO_IMPLICIT_CONFIGURE_LOG FALSE)
+
+Default is unset.