travis.yml: Drop the superfluous Python 3.6 build

Python 3.6 is already the default Python in the jobs that are based
on Ubuntu Bionic, so it does not make much sense to test this again
separately.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20200918103430.297167-7-thuth@redhat.com>
Message-Id: <20200925154027.12672-8-alex.bennee@linaro.org>

.travis.yml

@@ -262,14 +262,6 @@ jobs:
       python: 3.5
 
 
-    - name: "GCC Python 3.6 (x86_64-softmmu)"
-      env:
-        - CONFIG="--target-list=x86_64-softmmu"
-        - CACHE_NAME="${TRAVIS_BRANCH}-linux-gcc-default"
-      language: python
-      python: 3.6
-
-
     # Using newer GCC with sanitizers
     - name: "GCC9 with sanitizers (softmmu)"
       dist: bionic