[DOCS] Remove force as valid value for version_type parameter

[Gunnerva]

force is no longer a valid option for the version_type: flag -- this impacts at least version 6.8 and later.

Using force results in:

Error message from 6.8
{
"error": {
"root_cause": [
{
"type": "action_request_validation_exception",
"reason": "Validation Failed: 1: version type [force] may no longer be used;"
}
],
"type": "action_request_validation_exception",
"reason": "Validation Failed: 1: version type [force] may no longer be used;"
},
"status": 400
}

Error message from 7.6:
{
"error" : {
"root_cause" : [
{
"type" : "x_content_parse_exception",
"reason" : "[8:21] [dest] failed to parse field [version_type]"
}
],
"type" : "x_content_parse_exception",
"reason" : "[8:21] [reindex] failed to parse field [dest]",
"caused_by" : {
"type" : "x_content_parse_exception",
"reason" : "[8:21] [dest] failed to parse field [version_type]",
"caused_by" : {
"type" : "illegal_argument_exception",
"reason" : "No version type match [force]"
}
}
},
"status" : 400
}

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[elasticmachine]

Pinging @elastic/es-docs (>docs)

[elasticmachine]

Pinging @elastic/es-distributed (:Distributed/CRUD)

[jrodewig]

LGTM. Thanks for raising this @Gunnerva.

[jrodewig]

Backport commits

master 12e2485
7.x b4e203a
7.6 ab94fc0