ci(coverage): Set the correct out format for CI coverage reports

.github/workflows/coverage.yml

@@ -38,7 +38,7 @@ jobs:
       uses: actions-rs/cargo@v1
       with:
         command: tarpaulin
-        args: --workspace
+        args: --out Xml
 
     - name: Upload to codecov.io
       uses: codecov/codecov-action@v3

tarpaulin.toml

@@ -2,6 +2,7 @@
 debug = false
 verbose = false
 exclude-files = ["crates/matrix_sdk/examples/*"]
+workspace = true
 exclude = [
     "matrix-sdk-crypto-ffi",
     "matrix-sdk-crypto-js",