Function cleanupGoogleSheetsSheet

cleanupGoogleSheetsSheet(
    sheetName: string,
    sheetId: string,
    targetMonth: Date,
): Promise<void>
Cleans up a specific sheet in Google Sheets by removing targeted month's transactions. This function performs the following operations:
1. Fetches existing data from the specified sheets (expenses, incomes, investments).
2. Filters out transactions from the last month.
3. Writes the filtered data back to the respective sheets.
Parameters
- sheetName: string
  The name of the sheet to clean up.
- sheetId: string
  The Google Spreadsheet ID where the sheet is located.
- targetMonth: Date
  The month to filter out transactions for, in the format "MM-yyyy".
Returns Promise<void>
- Defined in src/features/googleSheetService.ts:216