CLDR-17402 json: drop _cldrVersion path

[srl295]

• drop //ldml/identity/version entirely (was producing _cldrVersion in every file)
• also, annotate the code working around CLDR-17790 as a TODO
• As a reminder, this will greatly reduce the diffs every time json is updated.

CLDR-17402

• This PR completes the ticket.

Example output with this change:

--- a/cldr-json/cldr-units-modern/main/zh/measurementSystemNames.json
+++ b/cldr-json/cldr-units-modern/main/zh/measurementSystemNames.json
@@ -2,9 +2,6 @@
   "main": {
     "zh": {
       "identity": {
-        "version": {
-          "_cldrVersion": "46"
-        },
         "language": "zh"
       },
       "localeDisplayNames": {

ALLOW_MANY_COMMITS=true

[btangmu]

There's still a lot of code involving "//ldml/identity/version" and this PR even adds a little bit more such code. Am I right in guessing that such paths are still required in some circumstances, such as in XML, even though they're no longer required in JSON?

[srl295]

There's still a lot of code involving "//ldml/identity/version" and this PR even adds a little bit more such code. Am I right in guessing that such paths are still required in some circumstances, such as in XML, even though they're no longer required in JSON?

• The data is part of the DTD, so needs to be present for backwards compatibility in XML.
• It's used in JSON, but it's extracted into the package manifest by other code.
• The version is read in XML by other Java code.