Add `*.cobertura.xml` to coverage file discovery patterns

[ScarletKuro]

Hi! I’d like to request adding this pattern to the default coverage file discovery list:

"*.cobertura.xml"

Current discovery includes:

"cobertura.xml"
"*coverage*.*"

but it does not include *.cobertura.xml.

This matters for .NET projects using the newer Microsoft Testing Platform v2 flow with Microsoft.Testing.Extensions.CodeCoverage. When running tests like this:

dotnet test -c Release --coverage --coverage-output-format cobertura --results-directory TestResults

Microsoft.CodeCoverage writes Cobertura reports with GUID-style filenames, for example:

TestResults/b4dc2cd6-7034-4454-b427-396a638ab386.cobertura.xml

That file is a valid Cobertura XML report, but Codecov automatic discovery misses it because:

"cobertura.xml"

only matches a file named exactly cobertura.xml, and the GUID filename does not match:

"*coverage*.*"

because it does not contain the word coverage.

The common workaround is to add a CI step that copies/renames the files:

mkdir -p coverage
i=0
for f in TestResults/*.cobertura.xml; do
  [ -e "$f" ] || continue
  i=$((i + 1))
  cp "$f" "coverage/coverage-$i.cobertura.xml"
done

This works, but it is unnecessary friction, especially as Microsoft Testing Platform v2 becomes the default path for modern .NET test projects. Multiple test projects/executables can each produce their own GUID-named .cobertura.xml report, so using one fixed output filename is not a good general solution either.

Adding *.cobertura.xml should be low risk because it matches a standard Cobertura naming convention and aligns with existing suffix-style patterns such as:

"*.lcov"
"*.gcov"
"*.clover"

Expected behavior:

Codecov automatic discovery should find files like:

TestResults/<guid>.cobertura.xml

without requiring users to rename or copy them.

Thanks!