remove strings dependency

os_release.v

@@ -1,7 +1,6 @@
 module os_release
 
 import os
-import strings
 
 // options contains list of default os-release, initrd-release, extension-release options.
 pub const options = ['NAME', 'ID', 'ID_LIKE', 'PRETTY_NAME', 'CPE_NAME', 'VARIANT', 'VARIANT_ID',
@@ -53,17 +52,17 @@ pub fn parse(content string) map[string]string {
 }
 
 fn unescape(s string) string {
-	mut ret := strings.new_builder(128)
+	mut ret := []u8{cap: 128}
 	for i := 0; i < s.len; i++ {
 		if (i == 0 || i == s.len - 1) && s[i] in [`"`, `'`] {
 			continue // trim leading and trailing quotes
 		}
 		if s[i] == `\\` && i + 1 < s.len {
-			ret.write_byte(s[i + 1])
+			ret << s[i + 1]
 			i++
 		} else {
-			ret.write_byte(s[i])
+			ret << s[i]
 		}
 	}
-	return ret.str()
+	return ret.bytestr()
 }