[build] Revert automatic regeneration of encoding tables

This is a regression added in 6.9.0. The table should stay stable.
Use manual bootstrap-tables to regenerate manually only.
Fixes #1119

ChangeLog

@@ -9,6 +9,7 @@
         + Fix Windows build for pbc_to_exe #1114
         + Fix default cygwin builds #1116
         + Silence failing auto::inline probe #1118
+        + Revert automatic regeneration of encoding tables, added with 6.9.0. #1119
     - Documentation
         + Document .lex "name" limitations. Use .lex 'name' w/ single-quotes #1095
     - Tests

config/gen/makefiles/root.in

@@ -906,9 +906,7 @@ $(RUN_INC_DIR)/config.fpmc : myconfig config_lib.pir \
 	@$(ADDGENERATED) "$@" "[]"
 
 # Check the generated tables before submitting updates.
-bootstrap-tables \
-  src/string/encoding/tables.h \
-  src/string/encoding/tables.c: tools/dev/gen_charset_tables.pl
+bootstrap-tables: tools/dev/gen_charset_tables.pl
 	$(PERL) tools/dev/gen_charset_tables.pl
 
 bootstrap-prt0: $(WINXED) $(FRPTWO_DIR)/prt0.winxed