Update dependency com.squareup.okio:okio to v3.9.1 (#322)

- Fix: Support paths containing a single dot (".") in `Path.relativeTo`.
- Fix: Do not read from the upstream source when a 0-byte read is
requested.
- Fix: Update kotlinx.datetime to 0.6.0 to correct a Gradle module
metadata problem with 0.5.0.
Note: this artifact is only used in 'okio-fakefilesystem' and
'okio-nodefilesystem' and not in the Okio core.

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

gradle/libs.versions.toml

@@ -5,7 +5,7 @@ openapi-generator = "7.8.0"
 jupyter-api = "0.12.0-285"
 jupyter-testkit = "0.12.0-285"
 jupyter-plugin = "0.12.0-285"
-okio = "3.9.0"
+okio = "3.9.1"
 moshi = "1.15.1"
 okhttp = "4.12.0"
 retrofit = "2.11.0"