gs1/gs1_lint: update to latest gs1-syntax-dictionary, removing

`iso3166list` linter and adjusting all others to allow for
  multiple optional linters (by checking `data_len` vs `offset`)
library: change invalid `input_mode` reset to return warning;
  split func table into 2 - func declarations without prototype
  will be error in C23;
  make invalid symbology check a separate function using a table
  and call near beginning of `ZBarcode_Encode_Segs()`;
  in `ZBarcode_BarcodeName()` save some bytes by simplifying
  name table and removing "BARCODE_" prefix from entries
output: fix pack logic to use pragma by default (actually more
  portable than `__attribute__`)
common.h: remove C99 detection which was artifice of specifying
  "-std=", and rejig layout to be more logical
BWIPP: update to latest version
general: change `ZINT_VERSION_BUILD` tests to `#if`s
general: further fiddling with some tables to save a few bytes
CLI: change function arg `optarg` -> `arg` so doesn't shadow
  global
general: library now compilable with Comp Cert C (though as it
  doesn't support `alloca()` will have multiple memory leaks)

docs/templates/styles.html

@@ -220,7 +220,7 @@ td {
 tbody tr:first-child td {
   padding-top: 0.5em;
 }
-header {
+thead > tr {
   margin-bottom: 4em;
   text-align: center;
 }