fix(spans): Make ActionSpan::new() private

ScorerSpan::new() was already private. This was never meant to be public.

BREAKING CHANGE: This function was previously public, but it was never meant to be used.

src/thinker.rs

@@ -43,7 +43,7 @@ pub struct ActionSpan {
 }
 
 impl ActionSpan {
-    pub fn new(action: Entity, label: Option<&str>) -> Self {
+    pub(crate) fn new(action: Entity, label: Option<&str>) -> Self {
         let span = span!(
             Level::DEBUG,
             "action",