refactor(span/source-type): make SourceType factories const

I found myself wanting this while writing `no-unused-vars` and while using oxc
in some downstream personal projects.

crates/oxc_span/src/source_type/mod.rs

@@ -69,15 +69,15 @@ impl SourceType {
     }
 
     #[must_use]
-    pub fn with_script(mut self, yes: bool) -> Self {
+    pub const fn with_script(mut self, yes: bool) -> Self {
         if yes {
             self.module_kind = ModuleKind::Script;
         }
         self
     }
 
     #[must_use]
-    pub fn with_module(mut self, yes: bool) -> Self {
+    pub const fn with_module(mut self, yes: bool) -> Self {
         if yes {
             self.module_kind = ModuleKind::Module;
         } else {
@@ -87,31 +87,31 @@ impl SourceType {
     }
 
     #[must_use]
-    pub fn with_typescript(mut self, yes: bool) -> Self {
+    pub const fn with_typescript(mut self, yes: bool) -> Self {
         if yes {
             self.language = Language::TypeScript;
         }
         self
     }
 
     #[must_use]
-    pub fn with_typescript_definition(mut self, yes: bool) -> Self {
+    pub const fn with_typescript_definition(mut self, yes: bool) -> Self {
         if yes {
             self.language = Language::TypeScriptDefinition;
         }
         self
     }
 
     #[must_use]
-    pub fn with_jsx(mut self, yes: bool) -> Self {
+    pub const fn with_jsx(mut self, yes: bool) -> Self {
         if yes {
             self.variant = LanguageVariant::Jsx;
         }
         self
     }
 
     #[must_use]
-    pub fn with_always_strict(mut self, yes: bool) -> Self {
+    pub const fn with_always_strict(mut self, yes: bool) -> Self {
         self.always_strict = yes;
         self
     }