fix: Use full environment names for py37 coverage exclusion

The tox environment names in GitHub Actions include the OS suffix
(e.g., py37-ubuntu-22.04), so we need to match the full names.

Author: taeold

tox.ini

@@ -35,7 +35,7 @@ setenv =
     PYTESTARGS = --cov=functions_framework --cov-branch --cov-report term-missing --cov-fail-under=100
     windows-latest: PYTESTARGS =
     # Python 3.7: Exclude aio module from coverage since it requires Python 3.8+ (Starlette dependency)
-    py37: PYTESTARGS = --cov=functions_framework --cov-branch --cov-report term-missing --cov-fail-under=100 --cov-omit='*/aio/*'
+    py37-{ubuntu-22.04,macos-13,windows-latest}: PYTESTARGS = --cov=functions_framework --cov-branch --cov-report term-missing --cov-fail-under=100 --cov-omit='*/aio/*'
 commands = pytest {env:PYTESTARGS} {posargs}
 
 [testenv:lint]