Update `LANG` environment variable same as Fedora and UBI

[srbala]

Update LANG environment variable same as Fedora and UBI, this will eliminiate the warnning in dnf shows as Failed to set locale, defaulting to C.UTF-8

https://pagure.io/fedora-kickstarts/blob/main/f/fedora-container-common.ks, https://bugzilla.redhat.com/show_bug.cgi?id=1727489

echo 'LANG="C.UTF-8"' >  /etc/locale.conf

$ docker run --rm -it almalinux  
[root@f5492cd44e6d /]# dnf search nodejs
Failed to set locale, defaulting to C.UTF-8
AlmaLinux 8 - BaseOS                                                                                         3.5 MB/s | 8.3 MB     00:02    
AlmaLinux 8 - AppStream                                                                                      3.3 MB/s | 9.0 MB     00:02    
AlmaLinux 8 - Extras                                                                                          24 kB/s |  10 kB     00:00    
======================================================= Name Exactly Matched: nodejs ========================================================
nodejs.x86_64 : JavaScript runtime
=========================================================== Name Matched: nodejs ============================================================
nodejs-devel.x86_64 : JavaScript runtime - development headers
nodejs-docs.noarch : Node.js API documentation
nodejs-full-i18n.x86_64 : Non-English locale data for Node.js
nodejs-nodemon.noarch : Simple monitor script for use during development of a node.js app
nodejs-packaging.noarch : RPM Macros and Utilities for Node.js Packaging
[root@f5492cd44e6d /]#

Locale from AlmaLinux

% docker run --rm -it almalinux
[root@03bf839edea1 /]# cat /etc/locale.conf
LANG="en_US.UTF-8"
[root@03bf839edea1 /]# locale
locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_MESSAGES to default locale: No such file or directory
locale: Cannot set LC_ALL to default locale: No such file or directory
LANG=en_US.UTF-8
LC_CTYPE="en_US.UTF-8"
LC_NUMERIC="en_US.UTF-8"
LC_TIME="en_US.UTF-8"
LC_COLLATE="en_US.UTF-8"
LC_MONETARY="en_US.UTF-8"
LC_MESSAGES="en_US.UTF-8"
LC_PAPER="en_US.UTF-8"
LC_NAME="en_US.UTF-8"
LC_ADDRESS="en_US.UTF-8"
LC_TELEPHONE="en_US.UTF-8"
LC_MEASUREMENT="en_US.UTF-8"
LC_IDENTIFICATION="en_US.UTF-8"
LC_ALL=
[root@03bf839edea1 /]#

Locale from UBI

% docker run --rm -it redhat/ubi8
[root@ca8449e6ae51 /]# cat /etc/locale.conf
LANG=C.utf8
[root@ca8449e6ae51 /]# locale
LANG=C.utf8
LC_CTYPE="C.utf8"
LC_NUMERIC="C.utf8"
LC_TIME="C.utf8"
LC_COLLATE="C.utf8"
LC_MONETARY="C.utf8"
LC_MESSAGES="C.utf8"
LC_PAPER="C.utf8"
LC_NAME="C.utf8"
LC_ADDRESS="C.utf8"
LC_TELEPHONE="C.utf8"
LC_MEASUREMENT="C.utf8"
LC_IDENTIFICATION="C.utf8"
LC_ALL=
[root@ca8449e6ae51 /]#