Update default RUST_VERSION to 1.86.0

Author: be-neth

conf/distro/include/rust_versions.inc

@@ -1,7 +1,7 @@
 # include this in your distribution to easily switch between versions
 # just by changing RUST_VERSION variable
 
-RUST_VERSION ?= "1.78.0"
+RUST_VERSION ?= "1.86.0"
 
 PREFERRED_VERSION_cargo ?= "${RUST_VERSION}"
 PREFERRED_VERSION_cargo-cross-canadian-${TARGET_ARCH} ?= "${RUST_VERSION}"