Bump django from 2.2.8 to 2.2.21#8

Bumps [django](https://github.com/django/django) from 2.2.8 to 2.2.21. <details> <summary>Commits</summary> <ul> <li><a href="https://github.com/django/django/commit/ff1385ae45d267f455b1744fb39a9ab5de688d05"><code>ff1385a</code></a> [2.2.x] Bumped version for 2.2.21 release.</li> <li><a href="https://github.com/django/django/commit/04ac1624bdc2fa737188401757cf95ced122d26d"><code>04ac162</code></a> [2.2.x] Fixed CVE-2021-31542 -- Tightened path &amp; file name sanitation in file...</li> <li><a href="https://github.com/django/django/commit/7f1b088ab4a4342a87a11496096471703994a006"><code>7f1b088</code></a> [2.2.x] Added CVE-2021-28658 to security archive.</li> <li><a href="https://github.com/django/django/commit/e95fbb6a7653a5f199d5d8c90a282cdf9e58fc22"><code>e95fbb6</code></a> [2.2.x] Post-release version bump.</li> <li><a href="https://github.com/django/django/commit/ad9fa56a17bf9691615e9bb6e41d08d51cfe8a5d"><code>ad9fa56</code></a> [2.2.x] Bumped version for 2.2.20 release.</li> <li><a href="https://github.com/django/django/commit/4036d62bda0e9e9f6172943794b744a454ca49c2"><code>4036d62</code></a> [2.2.x] Fixed CVE-2021-28658 -- Fixed potential directory-traversal via uploa...</li> <li><a href="https://github.com/django/django/commit/6e58828f8bcd33dfc91f236a972ae5fd23c9b0bc"><code>6e58828</code></a> [2.2.x] Added CVE-2021-23336 to security archive.</li> <li><a href="https://github.com/django/django/commit/1fb4628a83ab597da41bf88011a3b3ae1980b458"><code>1fb4628</code></a> [2.2.x] Post-release version bump.</li> <li><a href="https://github.com/django/django/commit/21a5547793a24357a985390970b489aeeca06d45"><code>21a5547</code></a> [2.2.x] Bumped version for 2.2.19 release.</li> <li><a href="https://github.com/django/django/commit/fd6b6afd5959b638c62dbf4839ccff97e7f7dfda"><code>fd6b6af</code></a> [2.2.x] Fixed CVE-2021-23336 -- Fixed web cache poisoning via django.utils.ht...</li> <li>Additional commits viewable in <a href="https://github.com/django/django/compare/2.2.8...2.2.21">compare view</a></li> </ul> </details> <br /> [](https://docs.github.com/en/github/managing-security-vulnerabilities/about-dependabot-security-updates#about-compatibility-scores) Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting `@dependabot rebase`. [//]: # (dependabot-automerge-start) [//]: # (dependabot-automerge-end) --- <details> <summary>Dependabot commands and options</summary> <br /> You can trigger Dependabot actions by commenting on this PR: - `@dependabot rebase` will rebase this PR - `@dependabot recreate` will recreate this PR, overwriting any edits that have been made to it - `@dependabot merge` will merge this PR after your CI passes on it - `@dependabot squash and merge` will squash and merge this PR after your CI passes on it - `@dependabot cancel merge` will cancel a previously requested merge and block automerging - `@dependabot reopen` will reopen this PR if it is closed - `@dependabot close` will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually - `@dependabot ignore this major version` will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself) - `@dependabot ignore this minor version` will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself) - `@dependabot ignore this dependency` will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself) - `@dependabot use these labels` will set the current labels as the default for future PRs for this repo and language - `@dependabot use these reviewers` will set the current reviewers as the default for future PRs for this repo and language - `@dependabot use these assignees` will set the current assignees as the default for future PRs for this repo and language - `@dependabot use this milestone` will set the current milestone as the default for future PRs for this repo and language You can disable automated security fix PRs for this repo from the [Security Alerts page](https://github.com/adorum/reality/network/alerts). </details>