Remove fan stress test from test plan (BugFix) (#763)

Removing for the following reasons:

1. This test case can't correctly identify the true pass/fail on each machine.
2. The fan is controlled by EC/ME on PC.
3. The cooling mechanism on INTEL platform is not using the increasing fan speed as the first priority.


Fix #697

providers/base/units/miscellanea/test-plan.pxu

@@ -31,7 +31,6 @@ include:
     firmware/fwts_uefirtvariable.*                 certification-status=blocker
     miscellanea/oops                               certification-status=blocker
     miscellanea/oops_results.log
-    miscellanea/fan_stress_reaction
     miscellanea/debsums                            certification-status=blocker
     miscellanea/check_prerelease                   certification-status=blocker
     miscellanea/ubuntu-desktop-recommends          certification-status=blocker

providers/sru/units/sru.pxu

@@ -56,7 +56,6 @@ include:
     audio/alsa_record_playback_automated
     install/apt-get-gets-updates
     miscellanea/dkms_build_validation
-    miscellanea/fan_stress_reaction
     networking/http
     networking/gateway_ping
     thunderbolt3/storage-preinserted
@@ -142,7 +141,6 @@ include:
     1_screenshot_fullscreen_video_.*.jpg
     install/apt-get-gets-updates
     miscellanea/dkms_build_validation
-    miscellanea/fan_stress_reaction
     networking/http
     networking/gateway_ping
     thunderbolt3/storage-preinserted