Bump protobuf from 3.6.0 to 3.18.3 in /examples/yoti_example_django

Bumps [protobuf](https://github.com/protocolbuffers/protobuf) from 3.6.0 to 3.18.3.
- [Release notes](https://github.com/protocolbuffers/protobuf/releases)
- [Changelog](https://github.com/protocolbuffers/protobuf/blob/main/generate_changelog.py)
- [Commits](protocolbuffers/protobuf@v3.6.0...v3.18.3)

---
updated-dependencies:
- dependency-name: protobuf
  dependency-type: indirect
...

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

Author: dependabot[bot]

examples/yoti_example_django/requirements.txt

@@ -32,7 +32,7 @@ idna==2.7
     # via requests
 iso8601==0.1.13
     # via yoti
-protobuf==3.6.0
+protobuf==3.18.3
     # via yoti
 pycparser==2.18
     # via cffi
@@ -49,7 +49,6 @@ requests==2.21.0
 six==1.11.0
     # via
     #   cryptography
-    #   protobuf
     #   pyopenssl
 sqlparse==0.3.0
     # via django
@@ -61,6 +60,3 @@ wrapt==1.12.1
     # via deprecated
 yoti==2.13.0
     # via -r requirements.in
-
-# The following packages are considered to be unsafe in a requirements file:
-# setuptools