Improve CI tests runtime (#457)

Before, Cosmos CI took approximately [18m
7s](https://github.com/astronomer/astronomer-cosmos/actions/runs/5823294146/usage)
to run its tests since it did not cache the dependencies.

Configure cache so the CI workers do not have to install all pip
dependencies at each CI job run.

Reduces test runtime to approximately
[12m-14m](https://github.com/astronomer/astronomer-cosmos/actions/runs/5854886292),
resulting in ~ 20-30% time savings to run tests in the CI.

.github/workflows/test.yml

@@ -34,6 +34,13 @@ jobs:
         with:
           ref: ${{ github.event.pull_request.head.sha || github.ref }}
 
+      - uses: actions/cache@v3
+        with:
+          path: |
+            ~/.cache/pip
+            .nox
+          key: unit-${{ runner.os }}-${{ matrix.python-version }}-${{ matrix.airflow-version }}-${{ hashFiles('pyproject.toml') }}-${{ hashFiles('cosmos/__init__.py') }}
+
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v4
         with:
@@ -62,11 +69,9 @@ jobs:
         airflow-version: ["2.3", "2.4", "2.5", "2.6"]
     services:
       postgres:
-        # Docker Hub image
         image: postgres
         env:
           POSTGRES_PASSWORD: postgres
-        # Set health checks to wait until postgres has started
         options: >-
           --health-cmd pg_isready
           --health-interval 10s
@@ -78,6 +83,12 @@ jobs:
       - uses: actions/checkout@v3
         with:
           ref: ${{ github.event.pull_request.head.sha || github.ref }}
+      - uses: actions/cache@v3
+        with:
+          path: |
+            ~/.cache/pip
+            .nox
+          key: integration-${{ runner.os }}-${{ matrix.python-version }}-${{ matrix.airflow-version }}-${{ hashFiles('pyproject.toml') }}-${{ hashFiles('cosmos/__init__.py') }}
 
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v4
@@ -118,10 +129,33 @@ jobs:
       matrix:
         python-version: ["3.10"]
         airflow-version: ["2.6"]
+
+    services:
+      postgres:
+        image: postgres
+        env:
+          POSTGRES_PASSWORD: postgres
+        options: >-
+          --health-cmd pg_isready
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
+        ports:
+          - 5432:5432
+
     steps:
       - uses: actions/checkout@v3
         with:
           ref: ${{ github.event.pull_request.head.sha || github.ref }}
+      - uses: actions/cache@v3
+        with:
+          path: |
+            ~/.cache/pip
+            .nox
+          key: integration-expensive-${{ runner.os }}-${{ matrix.python-version }}-${{ matrix.airflow-version }}-${{ hashFiles('pyproject.toml') }}-${{ hashFiles('cosmos/__init__.py') }}
+
+      - name: Checkout pull/${{ github.event.number }}
+        uses: actions/checkout@v3
 
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v4

pyproject.toml

@@ -162,15 +162,15 @@ test-integration = """pytest -vv \
 --cov-report=xml \
 --durations=0 \
 -m integration  \
--k 'not test_example_dag[example_cosmos_python_models]'
+-k 'not (test_example_dag[example_cosmos_python_models] or test_example_dag[example_virtualenv])'
 """
 test-integration-expensive = """pytest -vv \
 --cov=cosmos \
 --cov-report=term-missing \
 --cov-report=xml \
 --durations=0 \
 -m integration  \
--k 'test_example_dag[example_cosmos_python_models]'"""
+-k 'test_example_dag[example_cosmos_python_models] or test_example_dag[example_virtualenv]'"""
 
 [tool.pytest.ini_options]
 filterwarnings = [