Update dependency go to v1.24.3

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/openshift-upgrade-controller
 
 go 1.24
 
-toolchain go1.24.0
+toolchain go1.24.3
 
 require github.com/openshift/api v0.0.0-20240729140855-0a58f8c30a8c // release-4.15