fix(elisp): add lexical-binding comment to all files to suppress new Emacs 31 warnings

I've set `lexical-binding` to `nil` in all Emacs Lisp files to suppress
the warnings introduced in Emacs 31 requiring all elisp files to have a
`lexical-binding` comment.

This retains the default behavior of dynamic binding when no
`lexical-binding` comment is present. With it set to `t` across the
board, various things break, and fixing those is a task for another day.

modules/misc/siren-explain-pause.el

@@ -1,4 +1,4 @@
-;;; siren-explain-pause.el --- jimeh's Emacs Siren: explain-pause-mode configuration.
+;;; siren-explain-pause.el --- jimeh's Emacs Siren: explain-pause-mode configuration.  -*- lexical-binding: nil; -*-
 
 ;;; Commentary:
 

modules/misc/siren-grip.el

@@ -1,4 +1,4 @@
-;;; siren-grip.el --- jimeh's Emacs Siren: grip-mode configuration.
+;;; siren-grip.el --- jimeh's Emacs Siren: grip-mode configuration.  -*- lexical-binding: nil; -*-
 
 ;;; Commentary:
 

modules/misc/siren-list-available-fonts.el

@@ -1,4 +1,4 @@
-;;; siren-list-available-fonts.el --- jimeh's Emacs Siren: list-available-fonts helper.
+;;; siren-list-available-fonts.el --- jimeh's Emacs Siren: list-available-fonts helper.  -*- lexical-binding: nil; -*-
 
 ;;; Commentary:
 

modules/misc/siren-lorem-ipsum.el

@@ -1,4 +1,4 @@
-;;; siren-lorem-ipsum.el --- jimeh's Emacs Siren: lorem-ipsum configuration.
+;;; siren-lorem-ipsum.el --- jimeh's Emacs Siren: lorem-ipsum configuration.  -*- lexical-binding: nil; -*-
 
 ;;; Commentary:
 

modules/misc/siren-paradox.el

@@ -1,4 +1,4 @@
-;;; siren-paradox.el --- jimeh's Emacs Siren: paradox configuration.
+;;; siren-paradox.el --- jimeh's Emacs Siren: paradox configuration.  -*- lexical-binding: nil; -*-
 
 ;;; Commentary:
 

modules/misc/siren-rand.el

@@ -1,4 +1,4 @@
-;;; siren-rand.el --- jimeh's Emacs Siren: rand configuration.
+;;; siren-rand.el --- jimeh's Emacs Siren: rand configuration.  -*- lexical-binding: nil; -*-
 
 ;;; Commentary:
 

modules/misc/siren-refine.el

@@ -1,4 +1,4 @@
-;;; siren-refine.el --- jimeh's Emacs Siren: refine configuration.
+;;; siren-refine.el --- jimeh's Emacs Siren: refine configuration.  -*- lexical-binding: nil; -*-
 
 ;;; Commentary:
 

modules/misc/siren-reopen.el

@@ -1,4 +1,4 @@
-;;; siren-reopen.el --- jimeh's Emacs Siren: reopen helpers.
+;;; siren-reopen.el --- jimeh's Emacs Siren: reopen helpers.  -*- lexical-binding: nil; -*-
 
 ;;; Commentary:
 

modules/misc/siren-restart-emacs.el

@@ -1,4 +1,4 @@
-;;; siren-restart-emacs.el --- jimeh's Emacs Siren: restart-emacs configuration.
+;;; siren-restart-emacs.el --- jimeh's Emacs Siren: restart-emacs configuration.  -*- lexical-binding: nil; -*-
 
 ;;; Commentary:
 

modules/misc/siren-uuidgen.el

@@ -1,4 +1,4 @@
-;;; siren-uuidgen.el --- jimeh's Emacs Siren: uuidgen configuration.
+;;; siren-uuidgen.el --- jimeh's Emacs Siren: uuidgen configuration.  -*- lexical-binding: nil; -*-
 
 ;;; Commentary:
 

modules/misc/siren-zone.el

@@ -1,4 +1,4 @@
-;;; siren-zone.el --- jimeh's Emacs Siren: zone configuration.
+;;; siren-zone.el --- jimeh's Emacs Siren: zone configuration.  -*- lexical-binding: nil; -*-
 
 ;;; Commentary: