build: (deps): bump matrix from 6.2.0 to 7.0.0

Bumps [matrix](https://github.com/famedly/matrix-dart-sdk) from 6.2.0 to 7.0.0.
- [Release notes](https://github.com/famedly/matrix-dart-sdk/releases)
- [Changelog](https://github.com/famedly/matrix-dart-sdk/blob/main/CHANGELOG.md)
- [Commits](https://github.com/famedly/matrix-dart-sdk/compare/v6.2.0...v7.0.0)

---
updated-dependencies:
- dependency-name: matrix
  dependency-version: 7.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

pubspec.lock

@@ -1072,10 +1072,10 @@ packages:
     dependency: "direct main"
     description:
       name: matrix
-      sha256: "5bb38e98212bc4c3244c762a1af787f7239a38d2cfdf44488258283ff899f77c"
+      sha256: "0da5f65016c704bda81eae807cdadc18a046a444fa7e5cec83e60e5d04006d17"
       url: "https://pub.dev"
     source: hosted
-    version: "6.2.0"
+    version: "7.0.0"
   meta:
     dependency: transitive
     description: