kokoro: use python3 instead of specific 3.8 version

Signed-off-by: Alessandro Comodi <acomodi@antmicro.com>

.github/kokoro/steps/hostsetup.sh

@@ -87,14 +87,14 @@ sudo apt-get install -y \
         lsb \
         nodejs \
         psmisc \
-        python3.8 \
-        python3.8-dev \
-        python3.8-venv
+        python3 \
+        python3-dev \
+        python3-venv
 
 echo "========================================"
 echo "Enter virtual env for python 3.8"
 echo "----------------------------------------"
-python3.8 -mvenv startup_python
+python3 -mvenv startup_python
 source startup_python/bin/activate
 which python
 python --version

requirements.txt

@@ -1,6 +1,3 @@
--e third_party/fasm
--e third_party/python-sdf-timing
--e .
 intervaltree
 junit-xml
 numpy
@@ -10,9 +7,15 @@ parse
 progressbar2
 pyjson5
 pytest
+pytest-runner
 pyyaml
 scipy>=1.2.1
 simplejson
 sympy
 textx
 yapf==0.24.0
+
+# Third party
+-e third_party/fasm
+-e third_party/python-sdf-timing
+-e .