ci: increase build stage timeout to 3 hrs

This is what it was set to pre !741.

ci: increase build stage timeout to 3 hrs
This is what it was set to pre !741.
e19b1ef2 · Utkarsh Ayachit · 4f9bc802 · e19b1ef2
Commit e19b1ef2 authored Jul 22, 2020 by Utkarsh Ayachit ⛰
--- a/.gitlab/os-linux.yml
+++ b/.gitlab/os-linux.yml
@@ -116,6 +116,7 @@
            # Cache downloaded tarballs.
            - build/downloads/
    interruptible: true
+    timeout: 3 hours

 .cmake_test_linux:
    stage: test