Should I withdraw my pending I-829 if I have an approved I-130?

You will have to withdraw the I-829 at some point because conditional lawful permanent residents are not eligible to adjust status. The conditional status would have to be terminated first before the adjustment of status can be approved. You could do the withdrawal as close to possible to the adjustment of status interview and thus have a confirmation from the Immigrant Investor Program Office of the termination of your conditional status. If you wait until the adjustment of status interview, it could delay approval of your case because the interviewing officer will need to see proof of your status termination before approving the I-485.

If you did not have nonimmigrant status at the time you filed the adjustment, it may be denied. So I would not be that quick to withdraw the I-829. You should process the I-130 abroad, then formally surrender the I-407 while outside the U.S. and take it to your interview. These are complicated and need special handling. It is not about form filing but providing eligibility to adjust status under section 245 of the Act.

If I were you, I would do nothing and go to interview and have USCIS sort it out.

Until and unless your status is terminated you may not be able to adjust status on the I-130.