My resumes usually don't say "References provided upon request", because if the company wants them, they'll ask me anyways. I'm the same as you with colleagues

My resumes usually don't say "References provided upon request", because if the company wants them, they'll ask me anyways. I'm the same as you with colleagues, btw. I don't really burn bridges... but I do have trouble propping them up. I would just contact them anyways. I have done this with people I worked with 7 years ago and they could still reply with an "okay" for a reference.