Specify an environment for CI Actions config #1347

Performance Regression: -9.59%

❌ 2 regressed benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

	Mode	Benchmark	`BASE`	`HEAD`	Efficiency
❌	Simulation	`test_several_tools_add_and_remove`	810 ms	895.8 ms	-9.59%
❌	Simulation	`test_help_flag`	34.2 ms	36.6 ms	-6.43%

_{Comparing 1346-comply-with-secrets-outside-env-in-zizmor (189b217) with main (dbbaa67)}