Move CI build requirements to their own file so CMake doesn't get confused about them. They weren't really needed anyway for the CMake build.

docker_images/mbed-os-env/Dockerfile

@@ -49,7 +49,7 @@ RUN set -x \
     && pip3 install -r requirements.txt  \
     && : # last line
 
-COPY tools/test/requirements.txt .
+COPY tools/requirements-ci-build.txt .
 RUN set -x \
     && pip3 install -r requirements.txt  \
     && : # last line

tools/requirements-ci-build.txt

@@ -0,0 +1,7 @@
+# This file contains the requirements needed to run CI builds for Mbed OS.
+# It installs flashing support through the mbed tools packages and also the mbedhtrun test runner.
+mbed-tools
+mbed-host-tests
+mbed-greentea
+mbed-ls
+mbed-os-tools

tools/requirements.txt

@@ -2,9 +2,4 @@ PrettyTable<=1.0.1; python_version < '3.6'
 prettytable>=2.0,<3.0; python_version >= '3.6'
 future>=0.18.0,<1.0
 jinja2>=2.11.3
-intelhex>=2.3.0,<3.0.0
-mbed-tools
-mbed-host-tests
-mbed-greentea
-mbed-ls
-mbed-os-tools
+intelhex>=2.3.0,<3.0.0