Fix incorrect GET path in tasks.asciidoc

[kellycampbell]

Using GET /_cat/_tasks returns this error:

{"error":"Incorrect HTTP method for uri [/_cat/_tasks?v] and method [GET], allowed: [POST]","status":405}

Looking at the examples further down on the page, it should be tasks without the underscore.

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[cbuescher]

Hi @kellycampbell, thanks for rainsing this docs issue.
The second change looks good to me, I tried the first and was suprised it didn't work for me as expected on 7.4.2 (see comment). Maybe I'm missing something, but I'll wait for some feedback of the other to see how to proceed.

[cbuescher]

I just tried this on 7.4.2 and get something along the lines of

#! Deprecation: [types removal] Specifying types in document get requests is deprecated, use the /{index}/_doc/{id} endpoint instead.
{
  "error" : {
    "root_cause" : [
      {
        "type" : "index_not_found_exception",
        "reason" : "no such index [_cat]",
        "resource.type" : "index_expression",
        "resource.id" : "_cat",
        "index_uuid" : "_na_",
        "index" : "_cat"
      }
    ],
    "type" : "index_not_found_exception",
    "reason" : "no such index [_cat]",
    "resource.type" : "index_expression",
    "resource.id" : "_cat",
    "index_uuid" : "_na_",
    "index" : "_cat"
  },
  "status" : 404
}

which to me looks like the request is hitting the wrong endpoint (trying to index a document).
If this is the case, this might either be a bug we should file, or if getting tasks by id via the _cat API isn't supposed to be working we should remove this from the docs. Maybe @jrodewig or @imotov have an idea
how to proceed.

[jrodewig]

@cbuescher I'm seeing the same error on my end. I'll remove individual task retrieval from the docs. Thanks for raising this!

[elasticmachine]

Pinging @elastic/es-distributed (:Distributed/Task Management)

[elasticmachine]

Pinging @elastic/es-docs (>docs)

[jrodewig]

LGTM.

As @cbuescher pointed out, we need to remove the docs for individual task retrieval. I've raised #49550 to handle this.