While not universal this is actually a pretty acceptable practice in some fields, especially in the life sciences, where there are may subfields and your hiring committee may not be familiar with reputable journals in your field. I think it’s okay to include them.
This is actually an interesting and thought provoking question as impact factor for a journal does change over time. Personally, if relevant I’d use the most recent impact factor (usually for the last 5 years). My justification for this is 2 reasons: a) citations are cumulative over time b) this is what journals tend to use to reflect their current reputation. The citation from the 5 years before your publication may have informed your decision at the time but aren’t that relevant anymore as journal reputation can change and the 5 years preceding your publication didn’t include citations to your work.
It’s also worth noting that impact factor is not an ideal metric. While it is heavily used for hiring and promotion decisions and that should be acknowledged. It wasn’t its original purpose, the metric was designed not to measure quality of the work involved but for libraries to decide which journals are the most popular or important to subscribe to on a limited budget. This is inherently biased towards older established journals, controversial or hot topics, larger subfields, and review articles. It is also difficult to generalise as quality of research published within the same journal can vary widely, as can citations, and they’re not necessarily the same either. Journals newer than 5 years old cannot have an impact factor by definition. Some open access journals such as The Journal of Open Source Software have decided not to have one as it goes against the journal ethos.