chore(deps): update dependency go to v1.26.2

| datasource     | package | from   | to     |
| -------------- | ------- | ------ | ------ |
| golang-version | go      | 1.25.9 | 1.26.2 |


Signed-off-by: renovate-sh-app[bot] <219655108+renovate-sh-app[bot]@users.noreply.github.com>

Author: renovate-sh-app[bot]

go.mod

@@ -2,7 +2,7 @@ module go.k6.io/k6
 
 go 1.25.0
 
-toolchain go1.25.9
+toolchain go1.26.2
 
 require (
 	buf.build/gen/go/prometheus/prometheus/protocolbuffers/go v1.36.11-20260331160422-eae785f0a21d.1