build(deps): bump structlog from 21.2.0 to 21.5.0 in /requirements

Bumps [structlog](https://github.com/hynek/structlog) from 21.2.0 to 21.5.0.
- [Release notes](https://github.com/hynek/structlog/releases)
- [Changelog](https://github.com/hynek/structlog/blob/main/CHANGELOG.md)
- [Commits](hynek/structlog@21.2.0...21.5.0)

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

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

Author: dependabot[bot]

requirements/requirements-ci.txt

@@ -700,7 +700,7 @@ stack-data==0.2.0
     # via
     #   -r requirements-dev.txt
     #   ipython
-structlog==21.2.0
+structlog==21.5.0
     # via -r requirements-dev.txt
 threadloop==1.0.2
     # via

requirements/requirements-dev.txt

@@ -596,7 +596,7 @@ sortedcontainers==2.1.0
     #   matrix-synapse
 stack-data==0.2.0
     # via ipython
-structlog==21.2.0
+structlog==21.5.0
     # via -r requirements.txt
 threadloop==1.0.2
     # via

requirements/requirements.txt

@@ -267,7 +267,7 @@ six==1.16.0
     #   protobuf
     #   pyrsistent
     #   thrift
-structlog==21.2.0
+structlog==21.5.0
     # via -r requirements.in
 threadloop==1.0.2
     # via jaeger-client