Help: Update Sphinx versionadded directives for 3.22 release

Run the script:

    Utilities/Sphinx/update_versions.py --since v3.21.0 --overwrite

Manually select updates that really belong to the 3.22 release, as
against adding documentation for previously-existing entities.

Help/policy/CMP0127.rst

@@ -1,6 +1,8 @@
 CMP0127
 -------
 
+.. versionadded:: 3.22
+
 :command:`cmake_dependent_option` supports full :ref:`Condition Syntax`.
 
 The ``<depends>`` parameter accepts a :ref:`semicolon-separated list <CMake

Help/prop_test/ENVIRONMENT_MODIFICATION.rst

@@ -1,6 +1,8 @@
 ENVIRONMENT_MODIFICATION
 ------------------------
 
+.. versionadded:: 3.22
+
 Specify environment variables that should be modified for running a test. Note
 that the operations performed by this property are performed after the
 :prop_test:`ENVIRONMENT` property is already applied.

Help/prop_tgt/Fortran_BUILDING_INSTRINSIC_MODULES.rst

@@ -1,6 +1,8 @@
 Fortran_BUILDING_INSTRINSIC_MODULES
 -----------------------------------
 
+.. versionadded:: 3.22
+
 Instructs the CMake Fortran preprocessor that the target is building
 Fortran intrinsics for building a Fortran compiler.