tests: Shift pip install to run_jenkins_tests

Otherwise it's run as root rather than whatever user is being used
inside the container.

tests/python-baseline.Dockerfile

@@ -1,8 +1,6 @@
 FROM python:3.8.0
-LABEL maintainer="[email protected]"
 
-COPY requirements.txt /tmp/requirements.txt
-RUN pip install -r /tmp/requirements.txt && rm -f /tmp/requirements.txt
+LABEL maintainer="[email protected]"
 
 # setting Git username and email for workaround of
 # https://github.com/jenkinsci/docker/issues/519

tests/python-latest.Dockerfile

@@ -2,9 +2,6 @@ FROM python:latest
 
 LABEL maintainer="[email protected]"
 
-COPY requirements.txt /tmp/requirements.txt
-RUN pip install -r /tmp/requirements.txt && rm -f /tmp/requirements.txt
-
 # setting Git username and email for workaround of
 # https://github.com/jenkinsci/docker/issues/519
 ENV GIT_COMMITTER_NAME cheribuild

tests/run_jenkins_tests.sh

@@ -1,8 +1,5 @@
 #!/usr/bin/env bash
 
-pytest_binary="python3 -m pytest"
-
-
 case $1 in
   baseline|latest|ubuntu-baseline|ubuntu-latest)
     test_prefix=$1
@@ -30,6 +27,13 @@ else
     cd "$_srcdir"
 fi
 
+if ! python3 -m pip install --user -r requirements.txt; then
+  echo "FATAL: could not install requirements"
+  exit 1
+fi
+
+pytest_binary="python3 -m pytest"
+
 # Run unit tests
 rm -f "../$test_prefix-results.xml"
 $pytest_binary -v --junit-xml "../$test_prefix-results.xml" tests || echo "Some tests failed"

tests/ubuntu-baseline.Dockerfile

@@ -7,6 +7,3 @@ RUN apt-get update && apt-get install -y  --no-install-recommends \
   gcc \
   git \
   python3-minimal python3-pip python3-setuptools
-
-COPY requirements.txt /tmp/requirements.txt
-RUN pip3 install --user -r /tmp/requirements.txt && rm -f /tmp/requirements.txt

tests/ubuntu-latest.Dockerfile

@@ -7,6 +7,3 @@ RUN apt-get update && apt-get install -y  --no-install-recommends \
   gcc \
   git \
   python3-minimal python3-pip python3-setuptools
-
-COPY requirements.txt /tmp/requirements.txt
-RUN pip3 install --user -r /tmp/requirements.txt && rm -f /tmp/requirements.txt