test: move test-process-title to sequential

This test can fail when run in parallel with test-process-title-cli,
which also sets the process title, which is global state on Windows.

Example failure (note that `foo` does not appear in test-process-title
but in test-process-title-cli):

    not ok 1727 parallel/test-process-title
      ---
      duration_ms: 0.156
      severity: fail
      exitcode: 1
      stack: |-
        assert.js:103
          throw new AssertionError(obj);
          ^

        AssertionError [ERR_ASSERTION]: Expected values to be strictly equal:
        + actual - expected

        + 'foo'
        - 'd:\\a\\node\\node\\out\\Release\\node.exe'
            at Object.<anonymous> (d:\a\node\node\test\parallel\test-process-title.js:22:1)
            at Module._compile (internal/modules/cjs/loader.js:1176:30)
            at Object.Module._extensions..js (internal/modules/cjs/loader.js:1196:10)
            at Module.load (internal/modules/cjs/loader.js:1040:32)
            at Function.Module._load (internal/modules/cjs/loader.js:929:14)
            at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:71:12)
            at internal/main/run_main_module.js:17:47 {
          generatedMessage: true,
          code: 'ERR_ASSERTION',
          actual: 'foo',
          expected: 'd:\\a\\node\\node\\out\\Release\\node.exe',
          operator: 'strictEqual'
        }
      ...

(from https://github.com/nodejs/node/runs/628144750?check_suite_focus=true)

PR-URL: nodejs#33150
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Andrey Pechkurov <apechkurov@gmail.com>