Revert "build(deps): bump certifi from 2025.1.31 to 2025.4.26"

This reverts commit a5edd93531.

again, due to #1992, https://github.com/certifi/python-certifi/issues/349

I've pinned it with dependabot now, it shouldn't retry

requirements.txt

@@ -20,7 +20,7 @@ beautifulsoup4==4.13.4
 bech32==1.2.0
 cachetools==5.3.0
 cbor2==5.6.5
-certifi==2025.4.26
+certifi==2025.1.31
 cffi==1.17.1
 charset-normalizer==3.4.2
 click==8.1.8