fix: updated test for negative stride

---
type: pre_commit_static_analysis_report
description: Results of running static analysis checks when committing changes.
report:
  - task: lint_filenames
    status: passed
  - task: lint_editorconfig
    status: passed
  - task: lint_markdown
    status: na
  - task: lint_package_json
    status: na
  - task: lint_repl_help
    status: na
  - task: lint_javascript_src
    status: na
  - task: lint_javascript_cli
    status: na
  - task: lint_javascript_examples
    status: na
  - task: lint_javascript_tests
    status: passed
  - task: lint_javascript_benchmarks
    status: na
  - task: lint_python
    status: na
  - task: lint_r
    status: na
  - task: lint_c_src
    status: na
  - task: lint_c_examples
    status: na
  - task: lint_c_benchmarks
    status: na
  - task: lint_c_tests_fixtures
    status: na
  - task: lint_shell
    status: na
  - task: lint_typescript_declarations
    status: na
  - task: lint_typescript_tests
    status: na
  - task: lint_license_headers
    status: passed
---

---
type: pre_push_report
description: Results of running various checks prior to pushing changes.
report:
  - task: run_javascript_examples
    status: na
  - task: run_c_examples
    status: na
  - task: run_cpp_examples
    status: na
  - task: run_javascript_readme_examples
    status: na
  - task: run_c_benchmarks
    status: na
  - task: run_cpp_benchmarks
    status: na
  - task: run_fortran_benchmarks
    status: na
  - task: run_javascript_benchmarks
    status: na
  - task: run_julia_benchmarks
    status: na
  - task: run_python_benchmarks
    status: na
  - task: run_r_benchmarks
    status: na
  - task: run_javascript_tests
    status: passed
---

Author: 0PrashantYadav0

lib/node_modules/@stdlib/stats/base/snanmeanpn/test/test.ndarray.js

@@ -126,7 +126,7 @@ tape( 'the function supports a negative `stride` parameter', function test( t )
 		NaN   // 0
 	]);
 
-	v = snanmeanpn( 4, x, -2, 6 );
+	v = snanmeanpn( 5, x, -2, 8 );
 
 	t.strictEqual( v, 1.25, 'returns expected value' );
 	t.end();

lib/node_modules/@stdlib/stats/base/snanmeanpn/test/test.ndarray.native.js

@@ -135,7 +135,7 @@ tape( 'the function supports a negative `stride` parameter', opts, function test
 		NaN   // 0
 	]);
 
-	v = snanmeanpn( 4, x, -2, 6 );
+	v = snanmeanpn( 5, x, -2, 8 );
 
 	t.strictEqual( v, 1.25, 'returns expected value' );
 	t.end();