Fix dependency build for macOS (#18581)

* Add workflow file to cache key on macos job

* Remove reference to DD_PYTHON2 which is no longer set

* Trigger the build in master when the workflow file changes

.builders/images/macos-x86_64/builder_setup.sh

@@ -6,10 +6,6 @@ set -euxo pipefail
 "${DD_PYTHON3}" -m pip install --no-warn-script-location virtualenv
 "${DD_PYTHON3}" -m virtualenv py3
 
-"${DD_PYTHON2}" -m pip install --no-warn-script-location --upgrade pip
-"${DD_PYTHON2}" -m pip install --no-warn-script-location virtualenv
-"${DD_PYTHON2}" -m virtualenv py2
-
 # Install always with our own prefix path
 mkdir -p "${DD_PREFIX_PATH}"
 cp "${DD_MOUNT_DIR}/build_context/install-from-source.sh" .

.github/workflows/build-deps.yml

@@ -15,6 +15,7 @@ on:
     - master
     - 7.*.*
     paths:
+    - .github/workflows/build-deps.yml
     - .builders/**
     - agent_requirements.in
 
@@ -232,7 +233,7 @@ jobs:
       with:
         path: |
           ~/builder_root
-        key: macos-deps-builder-root-cache-${{ hashFiles('./.builders/images/macos/*', './.builders/images/*', './.builders/deps/*', './.builders/build.py') }}
+        key: macos-deps-builder-root-cache-${{ hashFiles('./.builders/images/macos/*', './.builders/images/*', './.builders/deps/*', './.builders/build.py', './.github/workflows/build-deps.yml') }}
 
     - name: Run the build
       env: