LPS-43671  Plugins SDK builds invalid CSS successfully when using failonerror to true in build-common.xml for SassToCssBuilder, try/finally added to resolve stuck build process for Master

- Ran "ant format-source"
- Ran "ant test-class -Dtest.class=SassToCssBuilderTest"
- Manually tested by modifying build-common.xml in liferay-plugins

Reference:
https://in.liferay.com/web/global.engineering/forums/-/message_boards/message/2280097#_19_message_2285124