remove std_cmake_args, std_pip_args, std_meson_args (#50462)

The "magic" globals `std_cmake_args`, `std_pip_args` and `std_meson_args` were deprecated in Spack 0.23 and removed in this commit, because they are no longer static and don't make sense to be defined for packages that do not depend on cmake, pip or meson.

Additionally, removing them ensures that `build_environment.py` no longer depends on builders, which will soon be moved out of `spack` into the `spack_repo` package.

The audit that scans whether these globals are used is not removed.

lib/spack/docs/packaging_guide.rst

@@ -2253,22 +2253,15 @@ RPATHs in Spack are handled in one of three ways:
    set in standard variables like ``CC``, ``CXX``, ``F77``, and ``FC``,
    so most build systems (autotools and many gmake systems) pick them
    up and use them.
-#. CMake also respects Spack's compiler wrappers, but many CMake
-   builds have logic to overwrite RPATHs when binaries are
-   installed. Spack provides the ``std_cmake_args`` variable, which
-   includes parameters necessary for CMake build use the right
-   installation RPATH.  It can be used like this when ``cmake`` is
-   invoked:
-
-   .. code-block:: python
-
-      class MyPackage(Package):
-          ...
-          def install(self, spec, prefix):
-              cmake("..", *std_cmake_args)
-              make()
-              make("install")
-
+#. CMake has its own RPATH handling, and distinguishes between build and
+   install RPATHs. By default, during the build it registers RPATHs to
+   all libraries it links to, so that just-built executables can be run
+   during the build itself. Upon installation, these RPATHs are cleared,
+   unless the user defines the install RPATHs. When inheriting from
+   ``CMakePackage``, Spack handles this automatically, and sets
+   ``CMAKE_INSTALL_RPATH_USE_LINK_PATH`` and ``CMAKE_INSTALL_RPATH``,
+   so that libraries of dependencies and the package's own libraries
+   can be found at runtime.
 #. If you need to modify the build to add your own RPATHs, you can
    use the ``self.rpath`` property of your package, which will
    return a list of all the RPATHs that Spack will use when it