Fix syntax-category of some punctuation characters

* lisp/textmodes/text-mode.el (text-mode-syntax-table): Don't
modify the global syntax-table just because we load text-mode.el.
This happens at loadup time, and then affects the default syntax
in all modes, not just in text-mode and its derivatives.
(Bug#49214)

lisp/textmodes/text-mode.el

@@ -49,7 +49,7 @@
     (modify-syntax-entry ?' "w p" st)
     ;; UAX #29 says HEBREW PUNCTUATION GERESH behaves like a letter
     ;; for the purposes of finding word boundaries.
-    (modify-syntax-entry #x5f3 "w   ") ; GERESH
+    (modify-syntax-entry #x5f3 "w   " st) ; GERESH
     ;; UAX #29 says HEBREW PUNCTUATION GERSHAYIM should not be a word
     ;; boundary when surrounded by letters.  Our infrastructure for
     ;; finding a word boundary doesn't support 3-character
@@ -57,13 +57,13 @@
     ;; character.  This leaves a problem of having GERSHAYIM at the
     ;; beginning or end of a word, where it should be a boundary;
     ;; FIXME.
-    (modify-syntax-entry #x5f4 "w   ") ; GERSHAYIM
+    (modify-syntax-entry #x5f4 "w   " st) ; GERSHAYIM
     ;; These all should not be a word boundary when between letters,
     ;; according to UAX #29, so they again are prone to the same
     ;; problem as GERSHAYIM; FIXME.
-    (modify-syntax-entry #xb7 "w   ")	; MIDDLE DOT
-    (modify-syntax-entry #x2027 "w   ")	; HYPHENATION POINT
-    (modify-syntax-entry #xff1a "w   ")	; FULLWIDTH COLON
+    (modify-syntax-entry #xb7 "w   " st)   ; MIDDLE DOT
+    (modify-syntax-entry #x2027 "w   " st) ; HYPHENATION POINT
+    (modify-syntax-entry #xff1a "w   " st) ; FULLWIDTH COLON
     st)
   "Syntax table used while in `text-mode'.")