chore: fix JavaScript lint errors (issue #11235)

[bhumikasudarshani-cmd]

Removed an unexpected empty line between require statements in
test.dgemv.native.js (line 42), which was causing the JavaScript
lint workflow to fail with stdlib/no-empty-lines-between-requires.

Resolves #11235

• [x]Read, understood, and followed the [contributing guidelines][contributing].

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
blas/base/dgemv	$\color{red}748/749$ $\color{green}+99.87%$	$\color{red}116/117$ $\color{green}+99.15%$	$\color{green}6/6$ $\color{green}+100.00%$	$\color{red}748/749$ $\color{green}+99.87%$

The above coverage report was generated for the changes in this PR.