Remove flex: 1 0 100% from rows (#31439)

Co-authored-by: XhmikosR <[email protected]>

Author: mdo

scss/mixins/_grid.scss

@@ -6,7 +6,6 @@
   --bs-gutter-x: #{$gutter};
   --bs-gutter-y: 0;
   display: flex;
-  flex: 1 0 100%;
   flex-wrap: wrap;
   margin-top: calc(var(--bs-gutter-y) * -1); // stylelint-disable-line function-blacklist
   margin-right: calc(var(--bs-gutter-x) / -2); // stylelint-disable-line function-blacklist