content: delete legacy_unit_directories

Change-Id: Ida13b26d63a1c2d627b4eceb9648f08d960d818b
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/297210
Trust: Julie Qiu <julie@golang.org>
Run-TryBot: Julie Qiu <julie@golang.org>
TryBot-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>

content/static/html/helpers/_unit_directories.tmpl

@@ -71,36 +71,3 @@
     {{- end -}}
   </tr>
 {{end}}
-
-{{define "legacy_unit_directories"}}
-  <div class="UnitDirectories js-unitDirectories" id="section-directories">
-    <h2 class="UnitDirectories-title">
-      <img height="25px" width="20px" src="/static/img/pkg-icon-folder_20x16.svg" alt="">Directories
-    </h2>
-    {{if (or .Subdirectories .NestedModules) }}
-      <table class="UnitDirectories-table" data-test-id="UnitDirectories-table">
-        <tr class="UnitDirectories-tableHeader">
-          <th>Path</th>
-          <th>Synopsis</th>
-        </tr>
-        {{range .Subdirectories}}
-          <tr>
-            <td>
-              <a href="{{.URL}}">{{.Suffix}}</a>
-            </td>
-            <td>{{.Synopsis}}</td>
-          </tr>
-        {{end}}
-        {{range .NestedModules}}
-          <tr>
-            <td>
-              <span class="UnitDirectories-moduleTag">MODULE</span>
-              <a href="{{.URL}}">{{.Suffix}}</a>
-            </td>
-            <td></td>
-          </tr>
-        {{end}}
-      </table>
-    {{end}}
-  </div>
-{{end}}