drop rust-installer.bbclass

This is only necessary for installations of rust so move the actual
functional bits into the do_install() phase of rust.

recipes-devtools/rust/rust.inc

@@ -403,6 +403,12 @@ rust_do_install () {
     # Remove any files directly installed into libdir to avoid
     # conflicts between cross and native
     rm -f ${D}${libdir}/lib*.so
+
+    # cleanup after rust-installer since we don't need these bits
+    rm ${D}/${libdir}/rustlib/install.log
+    rm ${D}/${libdir}/rustlib/rust-installer-version
+    rm ${D}/${libdir}/rustlib/uninstall.sh
+    rm ${D}/${libdir}/rustlib/components
 }
 
 do_install () {