Docs: Update whats-new-in-v7-4.md (#30876)

docs/sources/whatsnew/whats-new-in-v7-4.md

 +++
 +++
 title = "What's New in Grafana v7.4"
 title = "What's New in Grafana v7.4"
-description = "Feature and improvement highlights for Grafana v7.3"
-keywords = ["grafana", "new", "documentation", "7.3", "release notes"]
-aliases = ["/docs/grafana/latest/guides/whats-new-in-v7-3/"]
+description = "Feature and improvement highlights for Grafana v7.4"
+keywords = ["grafana", "new", "documentation", "7.4", "release notes"]
 weight = -31
 weight = -31
 [_build]
 [_build]
 list = false
 list = false