change run command for numericalnim (#19448)

Now it makes runs the custom `nimCI` task that installs the external dependencies

(cherry picked from commit 4b723c0)

testament/important_packages.nim

@@ -117,7 +117,7 @@ pkg "nimx", "nim c --threads:on test/main.nim", allowFailure = true
 pkg "nitter", "nim c src/nitter.nim", "https://github.com/zedeus/nitter"
 pkg "norm", "testament r tests/sqlite/trows.nim"
 pkg "npeg", "nimble testarc"
-pkg "numericalnim", "nim c -r tests/test_integrate.nim"
+pkg "numericalnim", "nimble nimCI"
 pkg "optionsutils"
 pkg "ormin", "nim c -o:orminn ormin.nim"
 pkg "parsetoml"