[12.x] Add test coverage for Process sequence with multiple env variables

[roshandelpoor]

This PR adds a new test case that verifies the interaction between process sequences and environment variables. The test ensures proper handling of multiple environment variables across sequential process executions.

Added testProcessWithMultipleEnvironmentVariablesAndSequences() to verify:

• Multiple environment variables can be set and read in a single process
• Process sequences return different values for the same environment variables
• Environment variables are correctly passed to processes
• Process sequences maintain state between calls

Related Issues

None