fix(lsp): handle out-of-bounds character positions #30288

Problem:
str_byteindex_enc could return an error if the index was longer than the
lline length. This was handled in each of the calls to it individually

Solution:
* Fix the call at the source level so that if the index is higher than
  the line length, line length is returned as per LSP specification
* Remove pcalls on str_byteindex_enc calls. No longer needed now that
  str_byteindex_enc has a bounds check.

runtime/lua/vim/lsp/inlay_hint.lua

@@ -77,12 +77,7 @@ function M.on_inlayhint(err, result, ctx, _)
     local col = position.character
     if col > 0 then
       local line = lines[position.line + 1] or ''
-      local ok, convert_result
-      ok, convert_result = pcall(util._str_byteindex_enc, line, col, client.offset_encoding)
-      if ok then
-        return convert_result
-      end
-      return math.min(#line, col)
+      return util._str_byteindex_enc(line, col, client.offset_encoding)
     end
     return col
   end