blueprint: always exclude the rescue kernel

Its BLS entry always expects a separate boot partition. Skip it on all
images until the rescue kernel package is usable.

tools/test_image_info/pipelines/ami_empty_blueprint.json

@@ -55,6 +55,9 @@
             "checkpolicy",
             "net-tools"
           ],
+          "exclude_packages": [
+            "dracut-config-rescue"
+          ],
           "releasever": "30",
           "basearch": "x86_64"
         }

tools/test_image_info/pipelines/openstack_empty_blueprint.json

@@ -55,6 +55,9 @@
             "cloud-init",
             "libdrm"
           ],
+          "exclude_packages": [
+            "dracut-config-rescue"
+          ],
           "releasever": "30",
           "basearch": "x86_64"
         }

tools/test_image_info/pipelines/vhd_empty_blueprint.json

@@ -54,6 +54,9 @@
             "WALinuxAgent",
             "libxcrypt-compat"
           ],
+          "exclude_packages": [
+            "dracut-config-rescue"
+          ],
           "releasever": "30",
           "basearch": "x86_64"
         }