wrf: explicit conflict oneapi + older versions (#44787)

The patch which enables icx/ifx compilers is only added for `wrf@4.4:`. This PR prints a useful message at concretization time instead of failing the installation later on.

Co-authored-by: stephenmsachs <stephenmsachs@users.noreply.github.com>

var/spack/repos/builtin/packages/wrf/package.py

@@ -256,6 +256,10 @@ class Wrf(Package):
     depends_on("m4", type="build")
     depends_on("libtool", type="build")
     depends_on("adios2", when="@4.5: +adios2")
+
+    conflicts(
+        "%oneapi", when="@:4.3", msg="Intel oneapi compiler patch only added for version 4.4"
+    )
     phases = ["configure", "build", "install"]
 
     def setup_run_environment(self, env):