Bump redis from 7.3.0 to 7.4.0 in /demos (#1786)

Bumps [redis](https://github.com/redis/redis-py) from 7.3.0 to 7.4.0.
- [Release notes](https://github.com/redis/redis-py/releases)
- [Changelog](https://github.com/redis/redis-py/blob/master/CHANGES)
- [Commits](redis/redis-py@v7.3.0...v7.4.0)

---
updated-dependencies:
- dependency-name: redis
  dependency-version: 7.4.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

demos/blog/requirements.txt

@@ -4,7 +4,7 @@ aiohttp-security[session]==0.5.0
 asyncpg==0.31.0
 bcrypt==5.0.0
 pytoml==0.1.21
-redis==7.3.0
+redis==7.4.0
 SQLalchemy==2.0.48
 
 # testing

demos/graphql-demo/requirements-dev.txt

@@ -8,7 +8,7 @@ graphene==2.1.9
 graphql-core==2.3.2
 graphql-ws==0.4.4
 psycopg2-binary==2.9.11
-redis==7.3.0
+redis==7.4.0
 
 mypy==1.19.1
 flake8==7.3.0

demos/shortify/requirements.txt

@@ -1,7 +1,7 @@
 aiohttp==3.13.4
 aiohttp-jinja2==1.6
 pyyaml==6.0.3
-redis==7.3.0
+redis==7.4.0
 trafaret==2.1.1
 pytest-aiohttp==1.1.0
 pytest-asyncio==1.3.0