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/workspaces/siren-desktop.el

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

modules/workspaces/siren-easysession.el

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

modules/workspaces/siren-elscreen.el

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

modules/workspaces/siren-escreen.el

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

modules/workspaces/siren-eyebrowse.el

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

modules/workspaces/siren-persp-mode.el

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

modules/workspaces/siren-perspective.el

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

modules/workspaces/siren-tab-bar.el

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

modules/workspaces/siren-workgroups2.el

@@ -1,4 +1,4 @@
-;;; siren-workgroups2.el --- jimeh's Emacs Siren: workgroups2 configuration.
+;;; siren-workgroups2.el --- jimeh's Emacs Siren: workgroups2 configuration.  -*- lexical-binding: nil; -*-
 
 ;;; Commentary:
 

modules/workspaces/siren-workspace-map.el

@@ -1,4 +1,4 @@
-;;; siren-workspace-map.el --- jimeh's Emacs Siren: workspaces-map setup.
+;;; siren-workspace-map.el --- jimeh's Emacs Siren: workspaces-map setup.  -*- lexical-binding: nil; -*-
 
 ;;; Commentary: