Bump go from 1.25.6 to v1.26.0

Author: dghubble-renovate[bot]

go.mod

@@ -2,7 +2,7 @@ module github.com/poseidon/github-runner
 
 go 1.24.0
 
-toolchain go1.25.6
+toolchain go1.26.0
 
 require (
 	github.com/bradleyfalzon/ghinstallation/v2 v2.17.0