chore: ignore accounts.pwd.yaml and remove duplicate gitignore entry

Adds */accounts.pwd.yaml to prevent credential files from being staged,
and removes the duplicate */osw_files/* entry that was auto-appended.

Author: LukasGold

.gitignore

@@ -66,3 +66,5 @@ playground
 
 # Automatically added by osw.auth.CredentialManager.save_credentials_to_file:
 */osw_files/*
+
+*/accounts.pwd.yaml