update changelog and upgrade notes

CHANGES.md

@@ -1,7 +1,7 @@
 Synapse 1.76.0 (2023-01-31)
 ===========================
 
-The 1.76 release is the first to enable faster joins ([MSC3706](https://github.com/matrix-org/matrix-spec-proposals/pull/3706) and [MSC3902](https://github.com/matrix-org/matrix-spec-proposals/pull/3902)) by default. Admins can opt-out: see [the upgrade notes](https://github.com/matrix-org/synapse/blob/release-v1.76/upgrade.md#faster-joins-are-enabled-by-default) for more details.
+The 1.76 release is the first to enable faster joins ([MSC3706](https://github.com/matrix-org/matrix-spec-proposals/pull/3706) and [MSC3902](https://github.com/matrix-org/matrix-spec-proposals/pull/3902)) by default. Admins can opt-out: see [the upgrade notes](https://github.com/matrix-org/synapse/blob/release-v1.76/docs/upgrade.md#faster-joins-are-enabled-by-default) for more details.
 
 The upgrade from 1.75 to 1.76 changes the account data replication streams in a backwards-incompatible manner. Server operators running a multi-worker deployment should consult [the upgrade notes](https://github.com/matrix-org/synapse/blob/release-v1.76/docs/upgrade.md#changes-to-the-account-data-replication-streams).
 

docs/upgrade.md

@@ -92,7 +92,7 @@ process, for example:
 
 ## Faster joins are enabled by default
 
-When joining a room for the first time, Synapse 1.76.0rc1 will request a partial join from the other server by default. Previously, server admins had to opt-in to this using an experimental config flag.
+When joining a room for the first time, Synapse 1.76.0 will request a partial join from the other server by default. Previously, server admins had to opt-in to this using an experimental config flag.
 
 Server admins can opt out of this feature for the time being by setting