fix(themes): apply intended hr styling in Ansum and Mapco article bodies (#8737)

The nested rule `.content, .content_thin { ... .content hr { ... } }`
in Ansum/_layout.css and Mapco/_layout.css expands the inner selector
to `.content .content hr` / `.content_thin .content hr`, which never
matches any markup. <hr> separators in article bodies have fallen
back to browser defaults instead of the styled rule (light grey 1px
line with soft shadow). Dating back to the SCSS sources from 2019
and preserved verbatim through the native-CSS conversion in #8241.

Drop the `.content` prefix on the inner selector so the rule applies
as `.content hr, .content_thin hr`.

Co-authored-by: Bjørn A. Andersen <polybjorn@users.noreply.github.com>

p/themes/Ansum/_layout.css

@@ -260,7 +260,7 @@ main.prompt {
 		line-height: 1.8rem;
 	}
 
-	.content hr {
+	hr {
 		margin: 30px 10px;
 		background: var(--grey-medium-light);
 		height: 1px;

p/themes/Ansum/_layout.rtl.css

@@ -260,7 +260,7 @@ main.prompt {
 		line-height: 1.8rem;
 	}
 
-	.content hr {
+	hr {
 		margin: 30px 10px;
 		background: var(--grey-medium-light);
 		height: 1px;

p/themes/Mapco/_layout.css

@@ -272,7 +272,7 @@ main.prompt {
 		line-height: 1.8rem;
 	}
 
-	.content hr {
+	hr {
 		margin: 30px 10px;
 		background: var(--grey-medium-light);
 		height: 1px;

p/themes/Mapco/_layout.rtl.css

@@ -272,7 +272,7 @@ main.prompt {
 		line-height: 1.8rem;
 	}
 
-	.content hr {
+	hr {
 		margin: 30px 10px;
 		background: var(--grey-medium-light);
 		height: 1px;