[metalos] Include {os_version} in PRETTY_NAME

Summary:
# This diff
Add the version to `os-release` PRETTY_NAME explicitly, this used to be included implicitly when {os_name} was set to "CentOS Stream X" but was removed in D47242191 to confirm with CentOS's standard value.

This value is used in ANR to set the value in serf, this diff results in serf OS strings of the form

`CentOS Stream 9 MclassicA`

Per this transform used by the os.py driver.

https://www.internalfb.com/code/fbsource/fbcode/machinechecker/anrsnapshot/drivers/os.py?lines=50-54

# Broader thoughts
The approach of executing a big shell command with conditional `cat` from various files is a bit wild. The additional naive parsing os the os-release format double so.

This driver probably needs a better rethink.

Test Plan:
## os-release File
```
devvm20063.prn0:~/fbsource/fbcode$ buck run metalos/os/facebook/classic/vmtest:switchroot-cached-c9 -- --shell=console
[root@vmtest ~]# cat /etc/os-release
NAME="CentOS Stream"
ID="centos"
VERSION="9"
PRETTY_NAME="CentOS Stream 9 MclassicA (0a658f98fcba6a779b2a123d1cfb83ad7da39966)"
IMAGE_ID="local"
IMAGE_LAYER="fbcode//metalos/os/facebook/classic:classic.c9"
IMAGE_VCS_REV="0a658f98fcba6a779b2a123d1cfb83ad7da39966"
IMAGE_VCS_REV_TIME="2023-07-17T14:07:19-0700"
VARIANT="MclassicA"
VARIANT_ID="mclassica"
ANSI_COLOR="0;34"
API_VER_KDUMP_SUBVOL="1"
API_VER_NETWORKD_ROUTES_IGNORE="1"
API_VER_SERVICE_IMAGE_GC="1"
API_VER_SERVICE_IMAGE_HELPER="1"
API_VER_SYSTEMD_KEXEC_LOAD="1"
API_VER_TMP_SUBVOL="2"
API_VER_TW_SUBVOL="1"
API_VER_USE_SYSTEMD_EXCEPTION="1"
```

Reviewed By: cooperlees

Differential Revision: D47529019

fbshipit-source-id: 33a4bf7a1fc4e3905757b4a44944dee5bb0d98ae

antlir/bzl/linux/release.bzl

@@ -89,7 +89,7 @@ cat > $OUT << EOF
 NAME="{os_name}"
 ID="{os_id}"
 VERSION="{os_version}"
-PRETTY_NAME="{os_name} {variant} ($rev)"
+PRETTY_NAME="{os_name} {os_version} {variant} ($rev)"
 IMAGE_ID="{image_id}"
 IMAGE_LAYER="{target}"
 IMAGE_VCS_REV="$rev"

antlir/bzl/linux/tests/test_os_release.py

@@ -41,7 +41,7 @@ def test_os_release(self) -> None:
         # Validate the Pretty Name has the names + a valid vcs rev
         self.assertTrue(
             re.match(
-                rf"AntlirTest\ Test\ \({rev_id_regex}\)",
+                rf"AntlirTest\ 9\ Test\ \({rev_id_regex}\)",
                 os_release["PRETTY_NAME"],
             )
         )