[E&A][REF] Removes version.stack attributes (#4008)

## Overview

Related to #2235

This PR removes the `version-stack` attributes from the Explore and
analyze and Reference sections as using those attributes could be
misleading. Some of these attributes are used as part of a download bash
command, which always points to the latest stack release. I left those
occurrences intact.

Author: szabosteve

explore-analyze/machine-learning/anomaly-detection/ml-limitations.md

@@ -11,7 +11,7 @@ products:
 
 # Anomaly detection limitations [ml-limitations]
 
-The following limitations and known problems apply to the {{version.stack}} release of the Elastic {{ml-features}}. The limitations are grouped into four categories:
+The following limitations and known problems apply to the Elastic {{ml-features}}. The limitations are grouped into four categories:
 
 * [Platform limitations](#ad-platform-limitations) are related to the platform that hosts the {{ml}} feature of the {{stack}}.
 * [Configuration limitations](#ad-config-limitations) apply to the configuration process of the {{anomaly-jobs}}.

explore-analyze/machine-learning/data-frame-analytics/ml-dfa-limitations.md

@@ -11,7 +11,7 @@ products:
 
 # Data frame analytics limitations [ml-dfa-limitations]
 
-The following limitations and known problems apply to the {{version.stack}} release of the Elastic {{dfanalytics}} feature. The limitations are grouped into the following categories:
+The following limitations and known problems apply to the Elastic {{dfanalytics}} feature. The limitations are grouped into the following categories:
 
 * [Platform limitations](#dfa-platform-limitations) are related to the platform that hosts the {{ml}} feature of the {{stack}}.
 * [Configuration limitations](#dfa-config-limitations) apply to the configuration process of the {{dfanalytics-jobs}}.

explore-analyze/machine-learning/nlp/ml-nlp-limitations.md

@@ -11,7 +11,7 @@ products:
 
 # NLP limitations [ml-nlp-limitations]
 
-The following limitations and known problems apply to the {{version.stack}} release of the Elastic {{nlp}} trained models feature.
+The following limitations and known problems apply to the Elastic {{nlp}} trained models feature.
 
 ## Document size limitations when using `semantic_text` fields [ml-nlp-large-documents-limit-10k-10mb]
 

explore-analyze/transforms/transform-limitations.md

@@ -11,7 +11,7 @@ products:
 
 # {{transforms-cap}} limitations [transform-limitations]
 
-The following limitations and known problems apply to the {{version.stack}} release of the Elastic {{transform}} feature. The limitations are grouped into the following categories:
+The following limitations and known problems apply to the Elastic {{transform}} feature. The limitations are grouped into the following categories:
 
 * [Configuration limitations](#transform-config-limitations) apply to the configuration process of the {{transforms}}.
 * [Operational limitations](#transform-operational-limitations) affect the behavior of the {{transforms}} that are running.

reference/fleet/running-on-kubernetes-managed-by-fleet.md

@@ -60,7 +60,7 @@ Download the manifest file, substituting `{agent_version}` with the version numb
 curl -L -O https://raw.githubusercontent.com/elastic/elastic-agent/refs/tags/v{agent_version}/deploy/kubernetes/elastic-agent-managed-kubernetes.yaml
 ```
 
-For example, to download the manifest of the latest {{version.stack}} release:
+For example, to download the manifest of the latest release:
 
 ```sh subs=true
 curl -L -O https://raw.githubusercontent.com/elastic/elastic-agent/refs/tags/v{{version.stack}}/deploy/kubernetes/elastic-agent-managed-kubernetes.yaml