I had an HDHP until mid January 2026 but no longer do. Can I still make a tax deductible HSA contribution if I put it toward my 2025 tax year limit?

I've had an HDHP for a few years but just recently switched to a different type of plan. The change in coverage happened about a week and a half ago, meaning while I do not have an HDHP now, I did have one for the entirety of 2025. Since I am still within the period where my HSA lets me make contributions toward the previous year's tax limit, can I make a contribution now, classify it as a tax year 2025 contribution, and deduct that on my 2025 taxes? Or will the IRS treat me as non-eligible even if contributing toward the previous year's limit?