Remove misleading `scons tests` build target (#19606)
Closes #16799
Summary of the issue:
The scons tests command only ran translation string comment checks (equivalent to scons checkPot), which was misleading since users expected it to run all tests.
Description of user facing changes:
None.
Description of developer facing changes:
The scons tests build target has been removed. Running scons tests now produces an explicit error message directing users to the correct commands:
scons checkPot for translation string checks
rununittests.bat for unit tests
runsystemtests.bat for system tests
runlint.bat for linting
Description of development approach:
Removed the tests/sconscript file that defined the misleading tests target.
Inlined the checkPot target definition from tests/sconscript into the main sconstruct file.
Added an explicit tests alias that raises SCons.Errors.UserError with a helpful error message, preventing SCons from silently succeeding due to the existing tests/ directory.
