build(deps): bump certifi from 2025.1.31 to 2025.6.15 in /docs

Bumps [certifi](https://github.com/certifi/python-certifi) from 2025.1.31 to 2025.6.15.
- [Commits](certifi/python-certifi@2025.01.31...2025.06.15)

---
updated-dependencies:
- dependency-name: certifi
  dependency-version: 2025.6.15
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

docs/requirements.txt

@@ -17,9 +17,9 @@ babel==2.17.0 \
     --hash=sha256:0c54cffb19f690cdcc52a3b50bcbf71e07a808d1c80d549f2459b9d2cf0afb9d \
     --hash=sha256:4d0b53093fdfb4b21c92b5213dba5a1b23885afa8383709427046b21c366e5f2
     # via sphinx
-certifi==2025.1.31 \
-    --hash=sha256:3d5da6925056f6f18f119200434a4780a94263f10d1c21d032a6f6b2baa20651 \
-    --hash=sha256:ca78db4565a652026a4db2bcdf68f2fb589ea80d0be70e03929ed730746b84fe
+certifi==2025.6.15 \
+    --hash=sha256:2e0c7ce7cb5d8f8634ca55d2ba7e6ec2689a2fd6537d8dec1296a477a4910057 \
+    --hash=sha256:d747aa5a8b9bbbb1bb8c22bb13e22bd1f18e9796defa16bab421f7f7a317323b
     # via requests
 charset-normalizer==3.4.1 \
     --hash=sha256:0167ddc8ab6508fe81860a57dd472b2ef4060e8d378f0cc555707126830f2537 \