Updates for modern macOS dev (#4242)

* Updates for modern macOS dev

Latest version of pip is needed, as well as a few config flags to show where to find graphviz (pygraphviz/pygraphviz#11 is somehow still helpful / relevant this many years on...)

Signed-off-by: Corey Quinn <QuinnyPig@users.noreply.github.com>
Co-authored-by: Chris Lalancette <clalancette@gmail.com>
(cherry picked from commit 1de6ff9)

# Conflicts:
#	source/Installation/Alternatives/macOS-Development-Setup.rst

source/Installation/Alternatives/macOS-Development-Setup.rst

@@ -83,7 +83,16 @@ You need the following things installed to build ROS 2:
 
    .. code-block:: bash
 
+<<<<<<< HEAD
       python3 -m pip install -U \
+=======
+      python3 -m pip install --upgrade pip
+
+      python3 -m pip install -U \
+        --config-settings="--global-option=build_ext" \
+        --config-settings="--global-option=-I$(brew --prefix graphviz)/include/" \
+        --config-settings="--global-option=-L$(brew --prefix graphviz)/lib/" \
+>>>>>>> 1de6ff98 (Updates for modern macOS dev (#4242))
         argcomplete catkin_pkg colcon-common-extensions coverage \
         cryptography empy flake8 flake8-blind-except==0.1.1 flake8-builtins \
         flake8-class-newline flake8-comprehensions flake8-deprecated \