Update CI installs to use PEP 508 direct-URL requirement syntax

Update CI installs to use PEP 508 direct-URL  instead of the deprecated `#egg=` fragment for VCS dependencies. Newer versions of `pip` now reject egg fragments containing extras (for example `#egg=mesa[network]`), which caused the weekly CI job to fail. The workflow now installs Mesa and Mesa-Geo from their `main` branches using `name[extra] @ git+URL`, restoring compatibility with current packaging tooling while keeping the existing behavior of testing against the latest upstream code.

Author: EwoutH

.github/workflows/test_examples.yml

@@ -55,6 +55,6 @@ jobs:
     - name: Install dependencies
       run: |
         pip install .[test]
-        pip install -U git+https://github.com/mesa/mesa@main#egg=mesa[network]
+        pip install -U "mesa[network] @ git+https://github.com/mesa/mesa@main"
     - name: Test with pytest
       run: pytest -rA -Werror -Wdefault::PendingDeprecationWarning test_examples.py

.github/workflows/test_gis_examples.yml

@@ -54,7 +54,7 @@ jobs:
         python-version: "3.12"
     - name: Install dependencies
       run: |
-        pip install -U git+https://github.com/mesa/mesa-geo@main#egg=mesa-geo
+        pip install -U "mesa-geo @ git+https://github.com/mesa/mesa-geo@main"
         pip install .[test_gis]
     - name: Test with pytest
       run: pytest -rA -Werror -Wdefault::PendingDeprecationWarning test_gis_examples.py --cov-report=xml