[Improve] Add user environment configuration script in conf directory

[limc5462]

What changes were proposed in this pull request

This PR introduces a user-environment configuration script in the conf directory. While streampark.sh attempts to load bin/setenv.sh, this file is not present by default. Placing this user-facing configuration in the conf/ directory aligns with the standard convention for configurable files. This provides a dedicated place for users to set custom environment variables (e.g., JAVA_HOME, HADOOP_HOME) that are specific to StreamPark without affecting the system-wide environment.

Brief change log

Verifying this change

This change is a trivial rework / code cleanup without any test coverage.

(or)

This change is already covered by existing tests, such as (please describe tests).

(or)

This change added tests and can be verified as follows:

Does this pull request potentially affect one of the following parts

• Dependencies (does it add or upgrade a dependency): no

[sonarqubecloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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