Bump okhttp from 3.14.4 to 3.14.6 in /core (testcontainers#2243)

Bumps [okhttp](https://github.com/square/okhttp) from 3.14.4 to 3.14.6.
- [Release notes](https://github.com/square/okhttp/releases)
- [Changelog](https://github.com/square/okhttp/blob/master/docs/changelog_3x.md)
- [Commits](square/okhttp@parent-3.14.4...parent-3.14.6)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

core/build.gradle

@@ -97,7 +97,7 @@ dependencies {
 
     shaded "org.yaml:snakeyaml:1.25"
 
-    shaded 'com.squareup.okhttp3:okhttp:3.14.4'
+    shaded 'com.squareup.okhttp3:okhttp:3.14.6'
 
     shaded 'org.glassfish.main.external:trilead-ssh2-repackaged:4.1.2'