style: Adjust font sizes in Calendar popover

- increase the font size definition for %smaller used by calendar
- drop numeric time style for weather box

Fixes: https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/7400
Fixes: https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/6024
Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/3313>

data/theme/gnome-shell-sass/_common.scss

@@ -291,7 +291,7 @@ stage {
 
 %smaller {
   font-weight: 400;
-  @include fontsize(8pt);
+  @include fontsize(9pt);
 }
 
 %monospace {font-family: monospace;}

data/theme/gnome-shell-sass/widgets/_calendar.scss

@@ -268,10 +268,9 @@
       spacing-columns: $base_padding * 2;
 
       .weather-forecast-time {
-        @extend %numeric;
-        @include fontsize(10pt);
-        padding-top: 0.2em;
-        padding-bottom: 0.4em;
+        @extend %smaller;
+        padding-top: $base_padding;
+        padding-bottom: $base_padding;
       }
       .weather-forecast-icon {
         icon-size: $large_scalable_icon_size;