Bump RAM on x86_64 machines to 3G

Workstation tests on Rawhide are getting OOM killed. Let's see
if this helps. All the other arches have this much already, and
the worker hosts can handle it.

Signed-off-by: Adam Williamson <awilliam@redhat.com>

templates.fif.json

@@ -7,7 +7,7 @@
                 "PART_TABLE_TYPE": "mbr",
                 "QEMUCPU": "Nehalem",
                 "QEMUCPUS": "2",
-                "QEMURAM": "2048",
+                "QEMURAM": "3072",
                 "QEMUVGA": "virtio",
                 "QEMU_VIRTIO_RNG": "1",
                 "WORKER_CLASS": "qemu_x86_64"
@@ -68,7 +68,7 @@
                 "PART_TABLE_TYPE": "gpt",
                 "QEMUCPU": "Nehalem",
                 "QEMUCPUS": "2",
-                "QEMURAM": "2048",
+                "QEMURAM": "3072",
                 "QEMUVGA": "virtio",
                 "QEMU_VIRTIO_RNG": "1",
                 "UEFI": "1",