chore(deps): bump solar-positioning from 0.6.1 to 0.7.0 in /backend

Bumps [solar-positioning](https://github.com/klausbrunner/solarpositioning-rs) from 0.6.1 to 0.7.0.
- [Changelog](https://github.com/klausbrunner/solarpositioning-rs/blob/main/CHANGELOG.md)
- [Commits](klausbrunner/solarpositioning-rs@v0.6.1...v0.7.0)

---
updated-dependencies:
- dependency-name: solar-positioning
  dependency-version: 0.7.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

backend/Cargo.lock

@@ -25,7 +25,7 @@ chrono = { version = "0.4", features = ["serde"] }
 chrono-tz = "0.10"
 quick-xml = "0.42"
 sun = "0.3"
-solar-positioning = "0.6"
+solar-positioning = "0.7"
 hmac = "0.13.0"
 sha1 = "0.11.0"
 md5 = "0.8.0"