Prevent slib to load all available srfis unconditionally

It was done long time ago (commit #3c1a03222a0fb0d16366a3684b41b39edb41d4d2)
but I seem to have reverted inadvertently after that.
Cf. #960

ChangeLog

@@ -1,3 +1,11 @@
+2023-11-10  Shiro Kawai  <shiro@acm.org>
+
+	* lib/slib.scm (slib:features): Exclude srfi-0 from slib:features
+	  to prevent slib initializer to load all available srfis, especially
+	  srfi.29.  It is mentioned in the comment immediately above, but
+	  I seem to have reverted the change when I updated slib.scm based
+	  on a newer template. https://github.com/shirok/Gauche/issues/960
+
 2023-11-03  Shiro Kawai  <shiro@acm.org>
 
 	* libsrc/file/util.scm (remove-directory*): Add :if-does-not-exit

lib/slib.scm

@@ -201,10 +201,10 @@
 
     ;; Other common features
 
-    ;; NB: we turned off srfi here, since if this is on, slib tries
+    ;; NB: we turned off srfi-0 here, since if this is on, slib tries
     ;; to import all available srfis, including srfi-29, which defines
     ;; incompatible 'format'.
-    srfi-0                           ;srfi-0, COND-EXPAND finds all srfi-*
+;;;    srfi-0                          ;srfi-0, COND-EXPAND finds all srfi-*
 ;;;    sicp                            ;runs code from Structure and
                                         ;Interpretation of Computer
                                         ;Programs by Abelson and Sussman.