[Antlir2][rhel8.8] Add rhel8.8 so that Antlir2 knows about it

Summary: Need to tell Antlir2 about rhel 8.8 to build image.

Test Plan: {gif:n2n6090v}

Reviewed By: vmagro

Differential Revision: D51870189

fbshipit-source-id: 8b7a38975db9afd4789094cd9bd6efb0deadf067

antlir/antlir2/bzl/image/cfg.bzl

@@ -68,6 +68,7 @@ def attrs_selected_by_cfg():
                 antlir2_dep("//antlir/antlir2/os:eln"): _rou_flavor_sel("eln"),
                 antlir2_dep("//antlir/antlir2/os:none"): antlir2_dep("//antlir/antlir2/flavor:none"),
                 antlir2_dep("//antlir/antlir2/os:rhel8"): antlir2_dep("//antlir/antlir2/facebook/flavor/rhel8:rhel8"),
+                antlir2_dep("//antlir/antlir2/os:rhel8.8"): antlir2_dep("//antlir/antlir2/facebook/flavor/rhel8.8:rhel8.8"),
                 # TODO: in D49383768 this will be disallowed so that we can
                 # guarantee that we'll never end up building a layer without
                 # configuring the os

antlir/antlir2/os/BUCK

@@ -37,3 +37,9 @@ os_version(
     family = "//antlir/antlir2/os/family:rhel",
     package_manager = "//antlir/antlir2/os/package_manager:dnf",
 )
+
+os_version(
+    name = "rhel8.8",
+    family = "//antlir/antlir2/os/family:rhel",
+    package_manager = "//antlir/antlir2/os/package_manager:dnf",
+)

antlir/antlir2/os/cfg.bzl

@@ -13,6 +13,7 @@ _OS_REFS = {
     "os.eln": antlir2_dep("//antlir/antlir2/os:eln"),
     "os.none": antlir2_dep("//antlir/antlir2/os:none"),
     "os.rhel8": antlir2_dep("//antlir/antlir2/os:rhel8"),
+    "os.rhel8.8": antlir2_dep("//antlir/antlir2/os:rhel8.8"),
     "os_constraint": antlir2_dep("//antlir/antlir2/os:os"),
     "os_family_constraint": antlir2_dep("//antlir/antlir2/os/family:family"),
 }