Fix typo when replacing go test with gotestsum

Very minor change to update the `go testsum` command to `gotestsum` (no space). Without it go will complain about the `testsum` command not being found.

This is correct in the example underneath, so this is just a consistency change.

pages/test_analytics/golang_collectors.md

@@ -12,7 +12,7 @@ To use Test Analytics with your [Go](https://go.dev/) language projects use [got
     go install gotest.tools/gotestsum@latest
     ```
 
-2. Use gotestsum to run your tests and output JUnit XML, by replacing `go test` with `go testsum`, for example:
+2. Use gotestsum to run your tests and output JUnit XML, by replacing `go test` with `gotestsum`, for example:
 
     ```sh
     gotestsum --junitfile junit.xml ./...