Bump go toolchain version to address CVE-2023-45288

Changes:
- Bump release-3.6 toolchain version to 1.22.2 due to CVE-2023-45288
- Update CHANGELOG-3.4, CHANGELOG-3.5, and CHANGELOG-3.6
- Bump go version in rw-heatmaps (which was still at 1.21 where
everything else is at 1.22)

Reference:
- PR etcd-io#17703

CHANGELOG/CHANGELOG-3.4.md

@@ -9,6 +9,9 @@ Previous change logs can be found at [CHANGELOG-3.3](https://github.com/etcd-io/
 ### Package `clientv3`
 - Add [requests retry when receiving ErrGPRCNotSupportedForLearner and endpoints > 1](https://github.com/etcd-io/etcd/pull/17692).
 
+### Dependencies
+- Compile binaries using [go 1.21.9](https://github.com/etcd-io/etcd/pull/17709).
+
 <hr>
 
 ## v3.4.31 (2024-03-21)

CHANGELOG/CHANGELOG-3.5.md

@@ -9,6 +9,9 @@ Previous change logs can be found at [CHANGELOG-3.4](https://github.com/etcd-io/
 ### Package `clientv3`
 - Add [requests retry when receiving ErrGPRCNotSupportedForLearner and endpoints > 1](https://github.com/etcd-io/etcd/pull/17641).
 
+### Dependencies
+- Compile binaries using [go 1.21.9](https://github.com/etcd-io/etcd/pull/17708).
+
 <hr>
 
 ## v3.5.13 (2024-03-29)

CHANGELOG/CHANGELOG-3.6.md

@@ -93,8 +93,8 @@ See [List of metrics](https://etcd.io/docs/latest/metrics/) for all metrics per
 - Add [`etcd_debugging_server_alarms`](https://github.com/etcd-io/etcd/pull/14276).
 
 ### Go
-- Require [Go 1.21+](https://github.com/etcd-io/etcd/pull/16594).
-- Compile with [Go 1.21+](https://go.dev/doc/devel/release#go1.21.minor). Please refer to [gc-guide](https://go.dev/doc/gc-guide) to configure `GOGC` and `GOMEMLIMIT` properly. 
+- Require [Go 1.22+](https://github.com/etcd-io/etcd/pull/16594).
+- Compile with [Go 1.22+](https://go.dev/doc/devel/release#go1.21.minor). Please refer to [gc-guide](https://go.dev/doc/gc-guide) to configure `GOGC` and `GOMEMLIMIT` properly. 
 
 ### Other
 

go.mod

@@ -2,7 +2,7 @@ module go.etcd.io/etcd/v3
 
 go 1.22
 
-toolchain go1.22.1
+toolchain go1.22.2
 
 replace (
 	go.etcd.io/etcd/api/v3 => ./api

tools/rw-heatmaps/go.mod

@@ -1,6 +1,6 @@
 module go.etcd.io/etcd/tools/rw-heatmaps/v3
 
-go 1.21
+go 1.22
 
 require (
 	github.com/spf13/cobra v1.8.0