fix: add dnf5 command for Fedora in RPM package instructions (#36527) (#36572)

Backport #36527 by @yshyuk

## Summary
Add support for Fedora 41+ which uses dnf5 with different command syntax
for adding repositories.

## Changes
- Added new locale key `packages.rpm.distros.fedora` for Fedora (dnf5)
- Added dnf5 command in RPM package template: `dnf config-manager
addrepo --from-repofile=<URL>`
- Kept existing dnf4 command (`--add-repo`) for RHEL/Rocky Linux
compatibility

## Background
Fedora 41+ uses dnf5 which has different syntax:
- **dnf4 (RHEL/Rocky):** `dnf config-manager --add-repo <URL>`
- **dnf5 (Fedora 41+):** `dnf config-manager addrepo
--from-repofile=<URL>`

Closes #35330

Co-authored-by: yshyuk <43194469+yshyuk@users.noreply.github.com>

Author: GiteaBot

templates/package/content/rpm.tmpl

@@ -14,6 +14,12 @@
 dnf config-manager --add-repo <origin-url data-url="{{AppSubUrl}}/api/packages/{{$.PackageDescriptor.Owner.Name}}/rpm{{$group}}.repo"></origin-url>
 {{- end}}
 
+# Fedora 41+ (DNF5)
+{{- range $group := .Groups}}
+	{{- if $group}}{{$group = print "/" $group}}{{end}}
+dnf config-manager addrepo --from-repofile=<origin-url data-url="{{AppSubUrl}}/api/packages/{{$.PackageDescriptor.Owner.Name}}/rpm{{$group}}.repo"></origin-url>
+{{- end}}
+
 # {{ctx.Locale.Tr "packages.rpm.distros.suse"}}
 {{- range $group := .Groups}}
 	{{- if $group}}{{$group = print "/" $group}}{{end}}