Fix flaky static initialization error

As seen in https://github.com/elastic/docs-builder/actions/runs/15775018706/job/44467383605?pr=1403#step:5:96

Author: reakaleek

tests/authoring/Inline/CrossLinks.fs

@@ -31,17 +31,20 @@ type ``cross-link makes it into html`` () =
 
 type ``error when using wrong scheme`` () =
 
-    static let markdown = Setup.Markdown """
-[APM Server binary](docs-x:/solutions/observability/apps/apm-server-binary.md)
-"""
-
     [<Fact>]
     let ``error on bad scheme`` () =
+        let markdown = Setup.Markdown """
+[APM Server binary](docs-x:/solutions/observability/apps/apm-server-binary.md)
+"""
         markdown
         |> hasError "'docs-x' was not found in the cross link index"
 
     [<Fact>]
-    let ``has no warning`` () = markdown |> hasNoWarnings
+    let ``has no warning`` () =
+        let markdown = Setup.Markdown """
+[APM Server binary](docs-x:/solutions/observability/apps/apm-server-binary.md)
+"""
+        markdown |> hasNoWarnings
 
 type ``error when bad anchor is used`` () =
 
@@ -143,4 +146,4 @@ type ``link to repository that does not resolve yet using double slashes`` () =
     let ``error when not found in links.json`` () = markdown |> hasError("'elasticsearch' was not found in the cross link index")
 
     [<Fact>]
-    let ``has no warning`` () = markdown |> hasNoWarnings
+    let ``has no warning`` () = markdown |> hasNoWarnings