Fix panic on server rebuilds when using both base templates and template.Defer

Fixes #12963

internal/js/esbuild/batch_integration_test.go

@@ -721,43 +721,3 @@ console.log("config.params.id", id3);
 	b.EditFileReplaceAll("assets/other/bar.css", ".bar-edit {", ".bar-edit2 {").Build()
 	b.AssertFileContent("public/mybundle/reactbatch.css", ".bar-edit2 {")
 }
-
-func TestEditBaseofManyTimes(t *testing.T) {
-	files := `
--- hugo.toml --
-baseURL = "https://example.com"
-disableLiveReload = true
-disableKinds = ["taxonomy", "term"]
--- layouts/_default/baseof.html --
-Baseof.
-{{ block "main" . }}{{ end }}
-{{ with (templates.Defer (dict "key" "global")) }}
-Now. {{ now }}
-{{ end }}
--- layouts/_default/single.html --
-{{ define "main" }}
-Single.
-{{ end }}
---
--- layouts/_default/list.html --
-{{ define "main" }}
-List.
-{{ end }}
--- content/mybundle/index.md --
----
-title: "My Bundle"
----
--- content/_index.md --
----
-title: "Home"
----
-`
-
-	b := hugolib.TestRunning(t, files)
-	b.AssertFileContent("public/index.html", "Baseof.")
-
-	for i := 0; i < 100; i++ {
-		b.EditFileReplaceAll("layouts/_default/baseof.html", "Now", "Now.").Build()
-		b.AssertFileContent("public/index.html", "Now..")
-	}
-}