Declare attributes only just before the include

These attributes are only used in the configuring-repositories-el module
which is only included in some cases. This makes it a bit more obvious
and avoids defining them for other cases.

guides/common/modules/proc_configuring-repositories.adoc

@@ -24,10 +24,6 @@ ifdef::foreman-el,katello,satellite[]
 [id="repositories-el-9"]
 == {EL} 9
 
-:distribution: el
-:distribution-major-version: 9
-:package-manager: dnf
-
 ifdef::satellite[]
 . Disable all repositories:
 +
@@ -49,6 +45,9 @@ ifdef::satellite[]
 endif::[]
 
 ifdef::foreman-el,katello[]
+:distribution: el
+:distribution-major-version: 9
+:package-manager: dnf
 include::proc_configuring-repositories-el.adoc[]
 endif::[]
 
@@ -57,10 +56,6 @@ include::snip_verification-enabled-repolist.adoc[]
 [id="repositories-el-8"]
 == {EL} 8
 
-:distribution: el
-:distribution-major-version: 8
-:package-manager: dnf
-
 ifdef::satellite[]
 . Disable all repositories:
 +
@@ -82,6 +77,9 @@ ifdef::satellite[]
 endif::[]
 
 ifdef::foreman-el,katello[]
+:distribution: el
+:distribution-major-version: 8
+:package-manager: dnf
 include::proc_configuring-repositories-el.adoc[]
 endif::[]