lsp: avoid pulling in treemacs/helm when their respective layers aren't enabled

CHANGELOG.develop

@@ -1833,6 +1833,8 @@ Other:
   - ~SPC m g S~ to find symbol in all projects
 - Deleted =fix-lsp-company-prefix= since =company-lsp= is doing that handling.
 - Fixed a delay when declaring prefixes for mode (thanks to Thanh Vuong)
+- Required =helm= or =treemacs= to download =helm-lsp= or =lsp-treemacs=
+  (thanks to Steven Allen)
 **** Debug Adapter Protocol (DAP)
 - Key bindings
   - ~SPC m d d e~ to edit debug template

layers/+tools/lsp/packages.el

@@ -14,8 +14,8 @@
     lsp-mode
     lsp-ui
     (company-lsp :requires company)
-    helm-lsp
-    lsp-treemacs
+    (helm-lsp :requires helm)
+    (lsp-treemacs :requires treemacs)
     popwin
     ))