dev-util/rust-script: use slotted rust

RUST_MIN_VER isn't working right now, but it should be fixed in
::gentoo soon.

Signed-off-by: Takuya Wakazono <pastalian46@gmail.com>

dev-util/rust-script/rust-script-0.35.0-r1.ebuild

@@ -106,6 +106,8 @@ CRATES="
 	winreg@0.52.0
 "
 
+RUST_MIN_VER="1.74.1"
+
 inherit cargo
 
 DESCRIPTION="Command-line tool to run Rust scripts which can make use of crates"
@@ -121,8 +123,6 @@ LICENSE+=" MIT MPL-2.0 Unicode-DFS-2016"
 SLOT="0"
 KEYWORDS="~amd64"
 
-BDEPEND=">=virtual/rust-1.74"
-
 QA_FLAGS_IGNORED="usr/bin/.*"
 
 PATCHES=(