Javascript dependency: Bump cssnano from 5.1.15 to 7.0.6 in /web

Bumps [cssnano](https://github.com/cssnano/cssnano) from 5.1.15 to 7.0.6.
- [Release notes](https://github.com/cssnano/cssnano/releases)
- [Commits](https://github.com/cssnano/cssnano/compare/cssnano@5.1.15...cssnano@7.0.6)

---
updated-dependencies:
- dependency-name: cssnano
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

web/package.json

@@ -107,7 +107,7 @@
     "chartjs-plugin-zoom": "^2.0.1",
     "codemirror": "^6.0.1",
     "convert-units": "^2.3.4",
-    "cssnano": "^5.0.2",
+    "cssnano": "^7.0.6",
     "date-fns": "^3.6.0",
     "diff-arrays-of-objects": "^1.1.8",
     "hotkeys-js": "^3.13.3",