MM-54963 - Update prepackaged calls to v0.21.0

Co-authored-by: Mattermost Build <build@mattermost.com>

server/Makefile

@@ -138,7 +138,7 @@ PLUGIN_PACKAGES ?= $(PLUGIN_PACKAGES:)
 PLUGIN_PACKAGES += mattermost-plugin-antivirus-v1.0.0
 PLUGIN_PACKAGES += mattermost-plugin-autolink-v1.4.0
 PLUGIN_PACKAGES += mattermost-plugin-aws-SNS-v1.2.0
-PLUGIN_PACKAGES += mattermost-plugin-calls-v0.20.0
+PLUGIN_PACKAGES += mattermost-plugin-calls-v0.21.0
 PLUGIN_PACKAGES += mattermost-plugin-channel-export-v1.0.0
 PLUGIN_PACKAGES += mattermost-plugin-confluence-v1.3.0
 PLUGIN_PACKAGES += mattermost-plugin-custom-attributes-v1.3.1