fix: Update d/ch for 23.10.60 to include space after name

format must be space between name and email address.

`-- maintainer-name <email-address> date`

No space resulted in error during build

```
W: livecd-rootfs: syntax-error-in-debian-changelog "badly formatted trailer line" [usr/share/doc/livecd-rootfs/changelog.gz:5]
W: livecd-rootfs: syntax-error-in-debian-changelog "found start of entry where expected more change data or trailer" [usr/share/doc/livecd-rootfs/changelog.gz:7]
```

debian/changelog

@@ -2,7 +2,7 @@ livecd-rootfs (23.10.60) mantic; urgency=medium
 
   * Add policy:unconfined_restrictions feature to 6.5 kernel (LP: #2062929) 
 
- -- Ankush Pathak<ankush.pathak@canonical.com>  Fri, 26 Apr 2024 12:37:55 -0500
+ -- Ankush Pathak <ankush.pathak@canonical.com>  Fri, 26 Apr 2024 12:37:55 -0500
 
 livecd-rootfs (23.10.59) mantic; urgency=medium