aerospikereceiver: Add missing units in metadata.yaml (open-telemetry#23572)

Metric unit is required, see:
https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/cmd/mdatagen/metadata-schema.yaml#L72-L73.

This PR adds the unit to metrics where this is missing:

- aerospike.node.query.tracked

Author: mackjmr

.chloggen/add-units-aerospikereceiver.yaml

@@ -0,0 +1,22 @@
+# Use this changelog template to create an entry for release notes.
+# If your change doesn't affect end users, such as a test fix or a tooling change,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: aerospikereceiver
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Adds unit to metrics where this was missing.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [23572]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext: |
+  Affected metrics can be found below.
+  - aerospike.node.query.tracked

receiver/aerospikereceiver/documentation.md

@@ -189,7 +189,7 @@ Number of queries which ran more than query untracked_time (default 1 sec), Aero
 
 | Unit | Metric Type | Value Type | Aggregation Temporality | Monotonic |
 | ---- | ----------- | ---------- | ----------------------- | --------- |
-|  | Sum | Int | Cumulative | true |
+| {queries} | Sum | Int | Cumulative | true |
 
 ## Resource Attributes
 

receiver/aerospikereceiver/internal/metadata/generated_metrics.go

@@ -141,6 +141,7 @@ metrics:
     enabled: true
     description: Number of queries tracked by the system.
     extended_documentation: Number of queries which ran more than query untracked_time (default 1 sec), Aerospike metric query_tracked
+    unit: '{queries}'
     sum:
       value_type: int
       input_type: string