Bump numpy from 1.18.5 to 1.21.0 in /tools/speech_data_explorer
Bumps [numpy](https://github.com/numpy/numpy) from 1.18.5 to 1.21.0.
<details>
<summary>Release notes</summary>
<p><em>Sourced from <a href="https://github.com/numpy/numpy/releases">numpy's releases</a>.</em></p>
<blockquote>
<h2>v1.21.0</h2>
<h1>NumPy 1.21.0 Release Notes</h1>
<p>The NumPy 1.21.0 release highlights are</p>
<ul>
<li>continued SIMD work covering more functions and platforms,</li>
<li>initial work on the new dtype infrastructure and casting,</li>
<li>universal2 wheels for Python 3.8 and Python 3.9 on Mac,</li>
<li>improved documentation,</li>
<li>improved annotations,</li>
<li>new <code>PCG64DXSM</code> bitgenerator for random numbers.</li>
</ul>
<p>In addition there are the usual large number of bug fixes and other
improvements.</p>
<p>The Python versions supported for this release are 3.7-3.9. Official
support for Python 3.10 will be added when it is released.</p>
<p>:warning:  Warning: there are unresolved problems compiling NumPy 1.21.0 with gcc-11.1 .</p>
<ul>
<li>Optimization level <code>-O3</code> results in many wrong warnings when running the tests.</li>
<li>On some hardware NumPy will hang in an infinite loop.</li>
</ul>
<h2>New functions</h2>
<h3>Add PCG64DXSM BitGenerator</h3>
<p>Uses of the PCG64 BitGenerator in a massively-parallel context have
been shown to have statistical weaknesses that were not apparent at the
first release in numpy 1.17. Most users will never observe this weakness
and are safe to continue to use PCG64. We have introduced a new
PCG64DXSM BitGenerator that will eventually become the new default
BitGenerator implementation used by <code>default_rng</code> in future releases.
PCG64DXSM solves the statistical weakness while preserving the
performance and the features of PCG64.</p>
<p>See <code>upgrading-pcg64</code> for more details.</p>
<p>(<a href="https://github-redirect.dependabot.com/numpy/numpy/pull/18906">gh-18906</a>)</p>
<h2>Expired deprecations</h2>
<ul>
<li>The <code>shape</code> argument <code>numpy.unravel_index</code> cannot be
passed as <code>dims</code> keyword argument anymore. (Was deprecated in NumPy
1.16.)</li>
</ul>
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</blockquote>
<p>... (truncated)</p>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a href="https://github.com/numpy/numpy/commit/b235f9e701e14ed6f6f6dcba885f7986a833743f"><code>b235f9e</code></a> Merge pull request <a href="https://github-redirect.dependabot.com/numpy/numpy/issues/19283">#19283</a> from charris/prepare-1.21.0-release</li>
<li><a href="https://github.com/numpy/numpy/commit/34aebc2824cf8c2bdbe19040b82f98f18557c8ba"><code>34aebc2</code></a> MAINT: Update 1.21.0-notes.rst</li>
<li><a href="https://github.com/numpy/numpy/commit/493b64bfe9c5396498325b87e5e80e1917555c41"><code>493b64b</code></a> MAINT: Update 1.21.0-changelog.rst</li>
<li><a href="https://github.com/numpy/numpy/commit/07d7e72ab6880c05b5fdd98482cf88982e778393"><code>07d7e72</code></a> MAINT: Remove accidentally created directory.</li>
<li><a href="https://github.com/numpy/numpy/commit/032fca5e2e9749b152ec56153f476e05efdff287"><code>032fca5</code></a> Merge pull request <a href="https://github-redirect.dependabot.com/numpy/numpy/issues/19280">#19280</a> from charris/backport-19277</li>
<li><a href="https://github.com/numpy/numpy/commit/7d25b81025a50cc0368f5727c65e875ca769469a"><code>7d25b81</code></a> BUG: Fix refcount leak in ResultType</li>
<li><a href="https://github.com/numpy/numpy/commit/fa5754e8c159a37fcd9345df261cf82821088ea0"><code>fa5754e</code></a> BUG: Add missing DECREF in new path</li>
<li><a href="https://github.com/numpy/numpy/commit/61127bb4d46d523b699da1b63abaa5035670da27"><code>61127bb</code></a> Merge pull request <a href="https://github-redirect.dependabot.com/numpy/numpy/issues/19268">#19268</a> from charris/backport-19264</li>
<li><a href="https://github.com/numpy/numpy/commit/143d45fff3ed9e051bdeef7bdb4df38025ea7d1c"><code>143d45f</code></a> Merge pull request <a href="https://github-redirect.dependabot.com/numpy/numpy/issues/19269">#19269</a> from charris/backport-19228</li>
<li><a href="https://github.com/numpy/numpy/commit/d80e4738f781a1d206bbc04a2e863299e5f2e104"><code>d80e473</code></a> BUG: Removed typing for == and != in dtypes</li>
<li>Additional commits viewable in <a href="https://github.com/numpy/numpy/compare/v1.18.5...v1.21.0">compare view</a></li>
</ul>
</details>
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