ref-manual/variables.rst: document INHIBIT_DEFAULT_RUST_DEPS

Fix [YOCTO #15755]

(From yocto-docs rev: 2eb345ffa74d58d209a6a8deb27b228c37628034)

Signed-off-by: Alper Ak <alperyasinak1@gmail.com>
Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
(cherry picked from commit fd143a04bab38f6aeec23ec229657b16fcaecdf1)
Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

documentation/ref-manual/variables.rst

@@ -4364,6 +4364,23 @@ system and gives an overview of their function and contents.
       Set the variable to "1" to prevent the default dependencies from
       being added.
 
+   :term:`INHIBIT_DEFAULT_RUST_DEPS`
+      Prevents the :ref:`ref-classes-rust` class from automatically adding
+      its default build-time dependencies.
+
+      When a recipe inherits the :ref:`ref-classes-rust` class, several
+      tools such as ``rust-native`` and ``${RUSTLIB_DEP}`` (only added when cross-compiling) are added
+      to :term:`DEPENDS` to support the ``rust`` build process.
+
+      To prevent the build system from adding these dependencies automatically,
+      set the :term:`INHIBIT_DEFAULT_RUST_DEPS` variable as follows::
+
+         INHIBIT_DEFAULT_RUST_DEPS = "1"
+
+      By default, the value of :term:`INHIBIT_DEFAULT_RUST_DEPS` is empty. Setting
+      it to "0" does not disable inhibition. Only the empty string will disable
+      inhibition.
+
    :term:`INHIBIT_PACKAGE_DEBUG_SPLIT`
       Prevents the OpenEmbedded build system from splitting out debug
       information during packaging. By default, the build system splits out