Help: Drop incorrect versionadded for try_compile result variable

In commit c705279bae (Help: Add `.. versionadded` directives to commands
documentation, 2020-11-08, v3.20.0-rc1~508^2) we accidentally added
``versionadded`` markup suggesting that the first argument to
`try_compile` was fixed as `RESULT_VAR` prior to CMake 3.14.  This was
probably due to misinterpreting the change from commit 7975edeac5 (Help:
User-provided variable names for try_* commands, 2019-02-24,
v3.14.0-rc3~16^2~3).

The result variable has never been fixed.  Drop the incorrect markup.

Help/command/try_compile.rst

@@ -19,10 +19,6 @@ Try Compiling Whole Projects
 Try building a project.  The success or failure of the ``try_compile``,
 i.e. ``TRUE`` or ``FALSE`` respectively, is returned in ``<resultVar>``.
 
-.. versionadded:: 3.14
-  The name of the ``<resultVar>`` is defined by the user.  Previously, it had
-  a fixed name ``RESULT_VAR``.
-
 In this form, ``<srcdir>`` should contain a complete CMake project with a
 ``CMakeLists.txt`` file and all sources.  The ``<bindir>`` and ``<srcdir>``
 will not be deleted after this command is run.  Specify ``<targetName>`` to
@@ -51,10 +47,6 @@ Try building an executable or static library from one or more source files
 variable).  The success or failure of the ``try_compile``, i.e. ``TRUE`` or
 ``FALSE`` respectively, is returned in ``<resultVar>``.
 
-.. versionadded:: 3.14
-  The name of the ``<resultVar>`` is defined by the user.  Previously, it had
-  a fixed name ``RESULT_VAR``.
-
 In this form, one or more source files must be provided.  If
 :variable:`CMAKE_TRY_COMPILE_TARGET_TYPE` is unset or is set to ``EXECUTABLE``,
 the sources must include a definition for ``main`` and CMake will create a

Help/command/try_run.rst

@@ -30,11 +30,6 @@ executable was built, but failed to run, then ``<runResultVar>`` will be
 set to ``FAILED_TO_RUN``.  See the :command:`try_compile` command for
 information on how the test project is constructed to build the source file.
 
-.. versionadded:: 3.14
-  The names of the result variables ``<runResultVar>`` and
-  ``<compileResultVar>`` are defined by the user.  Previously, they had
-  fixed names ``RUN_RESULT_VAR`` and ``COMPILE_RESULT_VAR``.
-
 The options are:
 
 ``CMAKE_FLAGS <flags>...``