fix(lang): prevent dockerfile-mode wrongfully activating certain files

This is a temporary workaround until this pull request is accepted and
merged: https://github.com/spotify/dockerfile-mode/pull/63

modules/languages/siren-dockerfile.el

@@ -7,13 +7,25 @@
 ;;; Code:
 
 (use-package dockerfile-mode
-  :mode
-  "/Dockerfile\\'"
-  "/Dockerfile\\.[^/]+\\'"
+  :hook
+  (dockerfile-mode . siren-dockerfile-mode-setup)
 
-  :hook (dockerfile-mode . siren-dockerfile-mode-setup)
+  ;; TODO: The auto-mode-alist customizations can be removed once this PR is
+  ;; merged: https://github.com/spotify/dockerfile-mode/pull/63
+  :mode
+  ;; Custom auto-mode-alist patterns requiring Dockerfiles to match of
+  ;; "Dockerfile", "Dockerfile.*", or "*.dockerfile".
+  "/Dockerfile\\(?:\\..*\\)?\\'"
+  "\\.dockerfile\\'"
 
   :init
+  ;; Delete default auto-mode-list from dockerfile-mode package, as it matches
+  ;; basically matches most filenames which contain "dockerfile", including this
+  ;; very file (siren-dockerfile.el).
+  (setq auto-mode-alist
+        (delete '("Dockerfile\\(?:\\..*\\)?\\'" . dockerfile-mode)
+                auto-mode-alist))
+
   (defun siren-dockerfile-mode-setup ()
     (subword-mode +1)))