Remove bogus ":safe t" custom properties

* lisp/org/oc.el (org-cite-global-bibliography)
(org-cite-note-rules, org-cite-punctuation-marks):
* lisp/org/oc-csl.el (org-cite-csl-locales-dir)
(org-cite-csl-styles-dir, org-cite-csl-no-citelinks-backends):
* lisp/org/oc-natbib.el (org-cite-natbib-options):
* lisp/org/org-keys.el (org-mouse-1-follows-link):
Remove bogus ":safe t" properties that would largely need to be
replaced by custom predicates.

lisp/org/oc-csl.el

@@ -127,7 +127,9 @@ If nil then only the fallback en-US locale will be available."
   :type '(choice
           (directory :tag "Locales directory")
           (const :tag "Use en-US locale only" nil))
-  :safe t)
+  ;; It's not obvious to me that arbitrary locations are safe.
+;;;  :safe #'string-or-null-p
+  )
 
 (defcustom org-cite-csl-styles-dir nil
   "Directory of CSL style files.
@@ -138,7 +140,9 @@ directory.  This variable is ignored when style file is absolute."
   :type '(choice
           (directory :tag "Styles directory")
           (const :tag "Use absolute file names" nil))
-  :safe t)
+  ;; It's not obvious to me that arbitrary locations are safe.
+;;;  :safe #'string-or-null-p
+  )
 
 ;;;; Citelinks
 (defcustom org-cite-csl-link-cites t
@@ -154,8 +158,7 @@ Cite linking for export back-ends derived from any of the back-ends listed here,
 is also disabled."
   :group 'org-cite
   :package-version '(Org . "9.5")
-  :type '(repeat symbol)
-  :safe t)
+  :type '(repeat symbol))
 
 ;;;; Output-specific variables
 (defcustom org-cite-csl-html-hanging-indent "1.5em"

lisp/org/oc-natbib.el

@@ -71,8 +71,7 @@ If \"natbib\" package is already required in the document, e.g., through
     (const :tag "order as above, but numerical citations are compressed if possible" sort&compress)
     (const :tag "display full author list on first citation, abbreviate the others" longnamesfirst)
     (const :tag "redefine \\thebibliography to issue \\section* instead of \\chapter*" sectionbib)
-    (const :tag "keep all the authors' names in a citation on one line" nonamebreak))
-  :safe t)
+    (const :tag "keep all the authors' names in a citation on one line" nonamebreak)))
 
 
 ;;; Internal functions

lisp/org/oc.el

@@ -127,8 +127,7 @@ File names must be absolute."
   :package-version '(Org . "9.5")
   :type '(choice (const :tag "No global bibliography" nil)
 		 (repeat :tag "List of bibliography files"
-                         (file :tag "Bibliography")))
-  :safe t)
+                         (file :tag "Bibliography"))))
 
 (defcustom org-cite-activate-processor 'basic
   "Processor used for activating citations, as a symbol."
@@ -295,8 +294,7 @@ This roughly follows the Oxford Guide to Style recommendations."
                   (const :tag "Citation next to punctuation" same))
           (choice :tag "Order of citation and punctuation"
                   (const :tag "Citation first" before)
-                  (const :tag "Citation last" after))))
-  :safe t)
+                  (const :tag "Citation last" after)))))
 
 (defcustom org-cite-punctuation-marks '("." "," ";" ":" "!" "?")
   "List of strings that can be moved around when placing note numbers.
@@ -306,8 +304,7 @@ allowed to shuffle punctuation marks specified in this list in order to
 place note numbers according to rules defined in `org-cite-note-rules'."
   :group 'org-cite
   :package-version '(Org . "9.5")
-  :type '(repeat string)
-  :safe t)
+  :type '(repeat string))
 
 
 ;;; Citation processors

lisp/org/org-keys.el

@@ -279,8 +279,7 @@ before org.el is loaded."
   :type '(choice
 	  (const :tag "A double click follows the link" double)
 	  (const :tag "Unconditionally follow the link with mouse-1" t)
-	  (integer :tag "mouse-1 click does not follow the link if longer than N ms" 450))
-  :safe t)
+	  (integer :tag "mouse-1 click does not follow the link if longer than N ms" 450)))
 
 (defcustom org-tab-follows-link nil
   "Non-nil means on links TAB will follow the link.