chore: revert undesired changes to ahavercos-by test

Restore original `new Array(5)` sparse array construction and
eslint-disable directives per maintainer review feedback. Only the
is-empty-collection test fix remains.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: travisbreaks

lib/node_modules/@stdlib/math/strided/special/ahavercos-by/test/test.main.js

@@ -74,17 +74,17 @@ tape( 'the function computes the inverse half-value versed cosine via a callback
 	ahavercosBy( x.length, x, 1, y, 1, accessor );
 	t.deepEqual( y, expected, 'deep equal' );
 
-	x = [];
-	x.length = 5; // sparse array
+	// eslint-disable-next-line stdlib/no-new-array
+	x = new Array( 5 ); // sparse array
 	y = [ 0.0, 0.0, 0.0, 0.0, 0.0 ];
 
 	expected = [ 0.0, 0.0, 0.0, 0.0, 0.0 ];
 
 	ahavercosBy( x.length, x, 1, y, 1, accessor );
 	t.deepEqual( y, expected, 'deep equal' );
 
-	x = [];
-	x.length = 5; // sparse array
+	// eslint-disable-next-line stdlib/no-new-array
+	x = new Array( 5 ); // sparse array
 	x[ 2 ] = rand();
 	y = [ 0.0, 0.0, 0.0, 0.0, 0.0 ];