Rename {if,when}! -> eval-{if,when}!

To better represent its purpose, as extensions to Emacs' eval-when*
API (for control flow at compile time).

modules/checkers/spell/config.el

@@ -64,7 +64,7 @@
 ;;
 ;;; Implementations
 
-(if! (not (featurep! +flyspell))
+(eval-if! (not (featurep! +flyspell))
 
     (use-package! spell-fu
       :when (executable-find "aspell")

modules/lang/python/config.el

@@ -309,8 +309,8 @@
 ;;
 ;;; LSP
 
-(when! (and (featurep! +lsp)
-            (not (featurep! :tools lsp +eglot)))
+(eval-when! (and (featurep! +lsp)
+                 (not (featurep! :tools lsp +eglot)))
 
   (use-package! lsp-python-ms
     :unless (featurep! +pyright)

modules/tools/magit/autoload.el

@@ -6,7 +6,7 @@
 ;;      support symlinks as unix knows them, so `magit-version' can't resolve
 ;;      its own repo's path.
 ;;;###autoload
-(when! IS-WINDOWS
+(eval-when! IS-WINDOWS
   (defadvice! +magit--ignore-version-a (&optional print-dest)
     :override #'magit-version
     (when print-dest