Bump trove-classifiers from 2021.7.10 to 2021.8.4

Bumps [trove-classifiers](https://github.com/pypa/trove-classifiers) from 2021.7.10 to 2021.8.4.
- [Release notes](https://github.com/pypa/trove-classifiers/releases)
- [Commits](https://github.com/pypa/trove-classifiers/commits)

---
updated-dependencies:
- dependency-name: trove-classifiers
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

requirements/main.txt

@@ -1022,9 +1022,9 @@ translationstring==1.4 \
     --hash=sha256:5f4dc4d939573db851c8d840551e1a0fb27b946afe3b95aafc22577eed2d6262 \
     --hash=sha256:bf947538d76e69ba12ab17283b10355a9ecfbc078e6123443f43f2107f6376f3
     # via pyramid
-trove-classifiers==2021.7.10 \
-    --hash=sha256:5a2cbd1def324b2fd1f43cd9472667caca1293e710f975db27aab1052b230ca5 \
-    --hash=sha256:ec3931212db4c0471d792aec1566b633cebae50d07706123399a94afc5141a97
+trove-classifiers==2021.8.4 \
+    --hash=sha256:04b2fb69badaae4d2adf148c7c70ee5b6a887dc29be31714b74449544fc1d410 \
+    --hash=sha256:5f7550db2ce42f27570881ebdff7c3984a8a8198a6d04878a79328b9ad102235
     # via -r requirements/main.in
 typeguard==2.12.1 \
     --hash=sha256:c2af8b9bdd7657f4bd27b45336e7930171aead796711bc4cfc99b4731bb9d051 \