Drop the toolchain and move minimum to 1.23

"If the toolchain line is omitted, the module or workspace is considered to have an implicit toolchain goV line, where V is the Go version from the go line."
https://go.dev/doc/toolchain

manageiq-operator/go.mod

@@ -1,8 +1,6 @@
 module github.com/ManageIQ/manageiq-pods/manageiq-operator
 
-go 1.22.0
-
-toolchain go1.22.6
+go 1.23
 
 require (
 	github.com/onsi/ginkgo/v2 v2.20.0