Release notes for Grafana 8.1.0

Alerting: Deduplicate receivers during migration. #36812, @codesome
ColorPicker: Display colors as RGBA. #37231, @nikki-kiga
Encryption: Add support for multiple encryption algorithms (aes-gcm). (Enterprise)
Select: Make portalling the menu opt-in, but opt-in everywhere. #37501, @ashharrison90
TeamSync: Batch team synchronization. (Enterprise)
TimeRangePicker: Improve accessibility. #36912, @tskarhed

Annotations: Correct annotations that are displayed upon page refresh. #37496, @axelavargas
Annotations: Fix Enabled button that disappeared from Grafana v8.0.6. #37454, @axelavargas
Annotations: Fix data source template variable that was not available for annotations. #37506, @axelavargas
AzureMonitor: Fix annotations query editor that does not load. #37476, @torkelo
Geomap: Fix scale calculations. #37375, @ryantxu
GraphNG: Fix y-axis autosizing. #37464, @leeoniya
Live: Display stream rate and fix duplicate channels in list response. #37365, @FZambia
Loki: Update labels in log browser when time range changes. #37520, @ivanahuckova
Loki: Update labels in log browser when time range changes in dashboard. #37541, @ivanahuckova
NGAlert: Send resolve signal to alertmanager on alerting -> Normal. #37363, @kylebrandt
PasswordField: Prevent a password from being displayed when you click the Enter button. #37444, @tskarhed
Renderer: Remove debug.log file when Grafana is stopped. #37367, @AgnesToulet
Security: Update dependencies to fix CVE-2021-36222. #37546, @ying-jeanne