Release notes for Grafana 8.3.4

Alerting: Allow configuration of non-ready alertmanagers. #43063, @alexweav
Alerting: Allow customization of Google chat message. #43568, @alexweav
Alerting: Allow customization of Google chat message (#43568). #43723, @alexweav
AppPlugins: Support app plugins with only default nav. #43016, @torkelo
InfluxDB: InfluxQL: query editor: skip fields in metadata queries. #42543, @gabor
Postgres/MySQL/MSSQL: Cancel in-flight SQL query if user cancels query in grafana. #43890, @mdvictor
Prometheus: Forward oauth tokens after prometheus datasource migration. #43686, @MasslessParticle

Azure Monitor: Bug fix for variable interpolations in metrics dropdowns. #43251, @sarahzinger
Azure Monitor: Improved error messages for variable queries. #43213, @sunker
CloudMonitoring: Fixes broken variable queries that use group bys. #43914, @sunker
Configuration: You can now see your expired API keys if you have no active ones. #42452, @ashharrison90
Elasticsearch: Fix handling multiple datalinks for a single field. #44029, @Elfo404
Export: Fix error being thrown when exporting dashboards using query variables that reference the default datasource. #44034, @ashharrison90
ImportDashboard: Fixes issue with importing dashboard and name ending up in uid. #43451, @torkelo
Login: Page no longer overflows on mobile. #43739, @ashharrison90
Plugins: Set backend metadata property for core plugins. #43349, @marefr
Prometheus: Fill missing steps with null values. #43622, @ivanahuckova
Prometheus: Fix interpolation of $__rate_interval variable. #44035, @ivanahuckova
Prometheus: Interpolate variables with curly brackets syntax. #42927, @ivanahuckova
Prometheus: Respect the http-method data source setting. #42753, @gabor
Table: Fixes issue with field config applied to wrong fields when hiding columns. #43376, @torkelo
Toolkit: Fix bug with rootUrls not being properly parsed when signing a private plugin. #43014, @dessen-xu
Variables: Fix so data source variables are added to adhoc configuration. #43881, @hugohaggmark