test: remove overused run from Bats

[AirQuick]

Remove redundant run from Bats, based on https://bats-core.readthedocs.io/en/stable/writing-tests.html#when-not-to-use-run .

[AirQuick]

For testing purposes, I changed this line:

 @test "SAXON_CP has precedence over SAXON_HOME" {
     export SAXON_HOME="${work_dir}/empty-saxon-home ${RANDOM}"
     mkdir "${SAXON_HOME}"
 
-    ../bin/xspec.sh ../tutorial/escape-for-regex.xspec
+    ../bin/xspec.sh -e ../tutorial/escape-for-regex.xspec
 }

and verified that the test failed:

$ test/run-bats.sh --filter "SAXON_CP"
 ✗ SAXON_CP has precedence over SAXON_HOME
   (in test file xspec.bats, line 169)
     `../bin/xspec.sh -e ../tutorial/escape-for-regex.xspec' failed
   Creating XSpec Directory at /tmp/xspec/bats_work/output_32447...
   
   Creating Test Stylesheet...
    
   
   Running Tests...
   Testing with SAXON HE 9.9.1.8
   No escaping
   Must not be escaped at all
   Test simple patterns
   ..When encountering parentheses
   escape them.
   ..When encountering a whitespace character class
   escape the backslash
   result should have one more character than source
   When processing a list of phrases
   All phrase elements should remain
   Strings should be escaped and status attributes should be added
         FAILED
   
   Formatting Report...
   passed: 5 / pending: 0 / failed: 1 / total: 6
   Report available at /tmp/xspec/bats_work/output_32447/escape-for-regex-result.html
   
   *** Found a test failure

1 test, 1 failure