Increase overall test timeout for nrfconnect. (#10191)

The nrfconnect workflow builds 10 example apps.  Each of those builds
takes 4-5 minutes.  That's 40-50 minutes right there.

Wither another 1-3 minutes each for container init and checkout, and
5+ minutes for bootstrap, it's fairly common to hit the 60 minute
overall timeout.

.github/workflows/examples-nrfconnect.yaml

@@ -25,7 +25,7 @@ concurrency:
 jobs:
     nrfconnect:
         name: nRF Connect SDK
-        timeout-minutes: 60
+        timeout-minutes: 90
 
         env:
             BUILD_TYPE: nrfconnect