lib: Update RedHatMono weight properties

This fixes a discussed issue[1] where Patternfly's default monospace
font gets incorrectly calculated as Red Hat Mono Light, which as 2
degrees thinner/lighter than medium.
Updating our overrides weight values to the ones used by Red Hat Mono[2]
pagckage should fix the issue,

[1] cockpit-project/cockpit-machines#1178 (comment)
[2] https://fontsource.org/fonts/red-hat-mono

pkg/lib/patternfly/_fonts.scss

@@ -32,7 +32,7 @@
 @include printRedHatFont(400, "Regular");
 @include printRedHatFont(700, "Bold", $familyName: "RedHatMono");
 @include printRedHatFont(700, "BoldItalic", $style: "italic", $familyName: "RedHatMono");
-@include printRedHatFont(300, "Italic", $style: "italic", $familyName: "RedHatMono");
-@include printRedHatFont(400, "Medium", $familyName: "RedHatMono");
-@include printRedHatFont(400, "MediumItalic", $style: "italic", $familyName: "RedHatMono");
-@include printRedHatFont(300, "Regular", $familyName: "RedHatMono");
+@include printRedHatFont(400, "Italic", $style: "italic", $familyName: "RedHatMono");
+@include printRedHatFont(500, "Medium", $familyName: "RedHatMono");
+@include printRedHatFont(500, "MediumItalic", $style: "italic", $familyName: "RedHatMono");
+@include printRedHatFont(400, "Regular", $familyName: "RedHatMono");