style(header-dividing): adjust dividing line position and background for improved appearance

chore(release): bump version to 1.2.5 in theme.yaml

theme.yaml

@@ -13,5 +13,5 @@ spec:
   repo: https://git.dev.cm/theme-terminal
   settingName: "theme-terminal-setting"
   configMapName: "theme-terminal-configMap"
-  version: 1.2.3
+  version: 1.2.5
   require: ">=2.22.0"