ci: reuse set-env.* across CI

[AirQuick]

This pull request reuses test/ci/set-env.* across CI, which reduces dependency on every CI system's whimsical configuration.

saxon-9-7 is not included in Travis CI in favor of GitHub Actions, because Travis CI is relatively slow nowadays.

Temporary commits

• aa748c9: Simulates a Bats test failure
• 84e6502: Simulates an XSpec unit test failure
• de1fc7b: Simulates an XSpec end-to-end test failure
• 4629770: Simulates a Maven package error
• d533554: Simulates a .class file discrepancy

They are to verify that the CI systems are still able to catch various test failures.

[commit-lint]

Continuous Integration

• reuse set-env.* across CI (f8d116e)
• fail in Bats deliberately (aa748c9)
• fail in an XSpec unit test deliberately (84e6502)
• fail in an XSpec end-to-end test deliberately (de1fc7b)
• fail in Maven package deliberately (4629770)
• fail in Compile Java stage deliberately (d533554)

Contributors

@AirQuick

[AirQuick]

Verified by the temporary commits. Merging this.