Hardcode protection of dnf5 package

Doing it this way, rather than using a file in /etc/dnf/protected.d,
means that DNF 4 will still be able to remove DNF 5. I think this is the
ideal functionality: DNF 4 will be able to remove DNF 5 and vice-versa,
but neither package manager will accidentally remove itself.

Resolves https://bugzilla.redhat.com/show_bug.cgi?id=2221907.

libdnf5/conf/config_main.cpp

@@ -293,7 +293,7 @@ class ConfigMain::Impl {
  OptionString proxy_username{nullptr};
  OptionString proxy_password{nullptr};
  OptionStringSet proxy_auth_method{"any", "any|none|basic|digest|negotiate|ntlm|digest_ie|ntlm_wb", false};
- OptionStringList protected_packages{resolve_globs("dnf glob:/etc/dnf/protected.d/*.conf")};
+ OptionStringList protected_packages{resolve_globs("dnf5 glob:/etc/dnf/protected.d/*.conf")};
  OptionString username{""};
  OptionString password{""};
  OptionBool gpgcheck{false};