Bump uvloop from 0.15.2 to 0.15.3

Bumps [uvloop](https://github.com/MagicStack/uvloop) from 0.15.2 to 0.15.3.
- [Release notes](https://github.com/MagicStack/uvloop/releases)
- [Commits](https://github.com/MagicStack/uvloop/compare/v0.15.2...v0.15.3)

---
updated-dependencies:
- dependency-name: uvloop
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

requirements.txt

@@ -9,7 +9,7 @@ python-dateutil==2.8.1
 pyyaml==5.4.1
 httpx[http2]==0.17.1
 Brotli==1.0.9
-uvloop==0.15.2; python_version >= '3.7'
+uvloop==0.15.3; python_version >= '3.7'
 uvloop==0.14.0; python_version < '3.7'
 httpx-socks[asyncio]==0.3.1
 langdetect==1.0.9