Use XZ compression for RPM packages

This is a follow-on to
https://gitlab.com/gitlab-org/omnibus-gitlab/-/merge_requests/7128
where we enabled XZ compression for DEB packages. Unfortunately, Omnibus
didn't do threaded compression for RPM packages because of the way it
was setting `_binary_payload`. That was causing XZ compression in
particular to take 2-3 times longer than GZip, so we could not merge
that change at the same time. With
https://gitlab.com/gitlab-org/omnibus/-/merge_requests/48 merged into
our fork, Omnibus will use threaded compression for RPM by default and
we can enable XZ compression for RPM packages as well.

Closes https://gitlab.com/gitlab-org/omnibus-gitlab/-/issues/8222

Changelog: changed

Author: Ryan Egesdahl

Gemfile.lock

@@ -1,7 +1,7 @@
 GIT
   remote: https://gitlab.com/gitlab-org/omnibus.git
-  revision: 358f4af204fe9b2899ab99e0c8975b97c13dddf5
-  tag: 9.0.19.0
+  revision: bed44a1bd07586f2338ffc04e9fc25b74154ad63
+  tag: 9.0.19.1
   specs:
     omnibus (9.0.19)
       aws-sdk-s3 (~> 1.116.0)

OMNIBUS_GEM_VERSION

@@ -1 +1 @@
-9.0.19.0
+9.0.19.1

config/projects/gitlab.rb

@@ -277,7 +277,7 @@
   signing_passphrase Gitlab::Util.get_env('GPG_PASSPHRASE')
 
   # Enable XZ compression if selected
-  compress_xz = Gitlab::Util.get_env('COMPRESS_XZ') || 'false'
+  compress_xz = Gitlab::Util.get_env('COMPRESS_XZ') || 'true'
   if compress_xz == 'true'
     compression_type :xz
     compression_level 6

doc/build/build_package.md

@@ -66,17 +66,14 @@ project's [Container Registry](https://gitlab.com/gitlab-org/gitlab-omnibus-buil
 
 1. By default, XZ compression is used to produce the final DEB package,
    which reduces the package size by nearly 30% in comparison to Gzip, with
-   little to no increase in build time. However, the system's package
-   manager must also support the format. If your system's package manager does
-   not support XZ packages, set the `COMPRESS_XZ` environment variable to `false`:
+   little to no increase in build time and a slight increase in installation
+   (decompression) time. However, the system's package manager must also support
+   the format. If your system's package manager does not support XZ packages,
+   set the `COMPRESS_XZ` environment variable to `false`:
 
    ```shell
    export COMPRESS_XZ=false
    ```
-   
-   NOTE: This is feature is disabled by default on RPM platforms due to an
-   as-yet-unexplained increase in packaging time. It can be enabled by setting
-   the `COMPRESS_XZ` environment variable to `true`.
 
 1. Install the libraries and other dependencies: