azure-pipelines.yml: Upgraded to macOS 10.15
azure-pipelines.yml: Upgraded to macOS 10.15

apache/lucenenet,jeme/lucenenet,apache/lucenenet,jeme/lucenenet,NightOwl888/lucenenet,apache/lucenenet,NightOwl888/lucenenet,jeme/lucenenet,jeme/lucenenet,NightOwl888/lucenenet,NightOwl888/lucenenet,apache/lucenenet