Bump splunk/splunk from 6.6.0 to 8.2.3 in /ci/splunk#1

dependabot[bot] wants to merge 1 commit intomasterstackrox/stackrox:masterfrom

dependabot/docker/ci/splunk/splunk/splunk-8.2.3stackrox/stackrox:dependabot/docker/ci/splunk/splunk/splunk-8.2.3Copy head branch name to clipboard