chore(deps): bump yfinance from 1.3.0 to 1.5.1 in /backend

Bumps [yfinance](https://github.com/ranaroussi/yfinance) from 1.3.0 to 1.5.1.
- [Release notes](https://github.com/ranaroussi/yfinance/releases)
- [Changelog](https://github.com/ranaroussi/yfinance/blob/main/CHANGELOG.rst)
- [Commits](https://github.com/ranaroussi/yfinance/compare/1.3.0...1.5.1)

---
updated-dependencies:
- dependency-name: yfinance
  dependency-version: 1.5.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

backend/pyproject.toml

@@ -38,7 +38,7 @@ dependencies = [
     "starlette==1.0.1",
     "vaderSentiment>=3.3.0",
     "uvicorn==0.34.0",
-    "yfinance==1.3.0",
+    "yfinance==1.5.1",
 ]
 
 [project.optional-dependencies]