chore: ignore new file in dot-idea directory (#227)

![CleanShot 2025-09-08 at 15.51.35@2x](/attachments/8133796b-eebf-4162-b6c4-f66d9217b48d)

Reviewed-on: https://gitea.angry.im/PeterCxy/OpenEUICC/pulls/227
Co-authored-by: septs <github@septs.pw>
Co-committed-by: septs <github@septs.pw>

.idea/.gitignore

@@ -1,14 +1,7 @@
-/shelf
-/caches
-/libraries
-/assetWizardSettings.xml
-/deploymentTarget*.xml
-/gradle.xml
-/misc.xml
-/modules.xml
-/navEditor.xml
-/runConfigurations.xml
-/workspace.xml
-/AndroidProjectSystem.xml
-
-**/*.iml
+*
+!/codeStyles/Project.xml
+!/codeStyles/codeStyleConfig.xml
+!/vcs.xml
+!/kotlinc.xml
+!/compiler.xml
+!/migrations.xml