infra: Adding Synopsys DesignCompiler label.

Signed-off-by: Tim 'mithro' Ansell <me@mith.ro>
diff --git a/.github/labels.yml b/.github/labels.yml
index b7494b0..7d5587e 100644
--- a/.github/labels.yml
+++ b/.github/labels.yml
@@ -254,3 +254,7 @@
 - name: "tools-Synopsys-PrimeTime"
   description: "Issues with using Synopsys Primetime with the PDK."
   color: "76fcf3"
+
+- name: "tools-Synopsys-DesignCompiler"
+  description: "Issues with using Synopsys Design Compiler with the PDK."
+  color: "76fcf3"