Made trybuild optional to fix MSRV of tests

Author: rodrimati1992

Cargo.toml

@@ -29,8 +29,10 @@ optional = true
 version = "0.7"
 default-features = false
 
-[dev-dependencies.trybuild]
+# no such thing as optional dev-dependencies, aaaaaaah
+[dependencies.trybuild]
 version = "1.0"
+optional = true
 
 [features]
 default = ["proc_macros"]
@@ -44,7 +46,7 @@ alloc = []
 mut_refs = ["rust_stable"]
 nightly_mut_refs = ["mut_refs"]
 docsrs = []
-__ui_tests = []
+__ui_tests = ["trybuild"]
 
 [package.metadata.docs.rs]
 features = ["alloc", "rust_stable", "nightly_mut_refs", "adt_const_marker", "docsrs"]