Update dependency go to v1.23.5

Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

go.mod

@@ -2,7 +2,7 @@ module github.com/appuio/appuio-cloud-agent
 
 go 1.23
 
-toolchain go1.23.3
+toolchain go1.23.5
 
 require (
 	github.com/appuio/control-api v0.33.4