refactor: (if|when)-let -> (if|when)-let*

With the former macros' future in the air (and likely to be targeted in
future, potentially breaking changes), I'll deal with this now than have
it bite me later.

Ref: https://lists.gnu.org/archive/html/emacs-devel/2024-10/msg00637.html

modules/config/default/autoload/search.el

@@ -77,7 +77,7 @@ If prefix ARG is set, include ignored/hidden files."
          (current-prefix-arg (unless (eq arg 'other) arg))
          (default-directory
            (if (eq arg 'other)
-               (if-let (projects (projectile-relevant-known-projects))
+               (if-let* ((projects (projectile-relevant-known-projects)))
                    (completing-read "Search project: " projects nil t)
                  (user-error "There are no known projects"))
              default-directory)))
@@ -101,7 +101,7 @@ If prefix ARG is set, prompt for a known project to search from."
    (list (or (doom-thing-at-point-or-region) "")
          (let ((projectile-project-root nil))
            (if current-prefix-arg
-               (if-let (projects (projectile-relevant-known-projects))
+               (if-let* ((projects (projectile-relevant-known-projects)))
                    (completing-read "Search project: " projects nil t)
                  (user-error "There are no known projects"))
              (doom-project-root default-directory)))))

modules/config/default/autoload/text.el

@@ -42,8 +42,8 @@
 (defun +default/yank-buffer-path (&optional root)
   "Copy the current buffer's path to the kill ring."
   (interactive)
-  (if-let (filename (or (buffer-file-name (buffer-base-buffer))
-                        (bound-and-true-p list-buffers-directory)))
+  (if-let* ((filename (or (buffer-file-name (buffer-base-buffer))
+                          (bound-and-true-p list-buffers-directory))))
       (let ((path (abbreviate-file-name
                    (if root
                        (file-relative-name filename root)