Bump Go version to 1.26.3 (#4000)

Bump Go version to 1.26.3

Signed-off-by: Aleksandr Ponimaskin <aleksandr.ponimaskin@zalando.de>

Author: a4180p

go.mod

@@ -326,4 +326,4 @@ require (
 	oras.land/oras-go/v2 v2.6.0 // indirect
 )
 
-go 1.26.2
+go 1.26.3