test: remove disk_file_creation_year to avoid year update maintenance

Author: Lorilatschki

tests/attrs_and_props/license.txt

@@ -4,4 +4,3 @@ props["copyrightOwner"]={{props["copyrightOwner"]}}
 attrs.filename={{attrs.filename}}
 attrs.git_file_created_year={{attrs.git_file_created_year}}
 attrs.git_file_modified_year={{attrs.git_file_modified_year}}
-attrs.disk_file_creation_year={{attrs.disk_file_creation_year}}

tests/attrs_and_props/main.rs.expected

@@ -4,7 +4,6 @@
 // attrs.filename=main.rs
 // attrs.git_file_created_year=2025
 // attrs.git_file_modified_year=2025
-// attrs.disk_file_creation_year=2025
 
 fn main() {
     println!("Hello, world!");