fix(Table): update invalid line-height value (#5363)

* fix(Table): update invalid line-height value

* chore: add changeset

Author: joshblack

.changeset/healthy-humans-chew.md

@@ -0,0 +1,5 @@
+---
+"@primer/react": patch
+---
+
+Update line-height value for Table to be a valid calc() expression

packages/react/src/DataTable/Table.tsx

@@ -31,7 +31,7 @@ const StyledTable = styled.table<React.ComponentPropsWithoutRef<'table'>>`
   display: grid;
   font-size: var(--table-font-size);
   grid-template-columns: var(--grid-template-columns);
-  line-height: calc(20 / var(--table-font-size));
+  line-height: calc(20 / 12);
   width: 100%;
 
   /* Density modes: condensed, normal, spacious */