[chore] [exporter/clickhouse] Upgrade trace stability to beta (#35186)

**Description:**

This PR upgrades the status of traces to _beta_ to properly reflect its
stability. This is similar to the recent upgrade PR for logs (#33615)

Configuration options are unlikely to change for traces, and the
exporter has proven to be stable for both traces and logs. Table schema
may be subject to change as query optimizations are added in ClickHouse.
Metrics will remain in alpha for now.

Thanks!

**Documentation:**
- Updated metadata.yaml
- Updated README
- Re-ran `make generate`

.chloggen/clickhouse-trace-stability.yaml

@@ -0,0 +1,29 @@
+# Use this changelog template to create an entry for release notes.
+
+# 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: clickhouseexporter
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Upgrading stability for traces to beta
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [35186]
+
+# (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: |
+  The trace exporter has proven to be stable for production deployments.
+  Trace configuration is unlikely to receive any significant changes.
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

exporter/clickhouseexporter/README.md

@@ -3,8 +3,8 @@
 <!-- status autogenerated section -->
 | Status        |           |
 | ------------- |-----------|
-| Stability     | [alpha]: traces, metrics   |
-|               | [beta]: logs   |
+| Stability     | [alpha]: metrics   |
+|               | [beta]: traces, logs   |
 | Distributions | [contrib] |
 | Issues        | [![Open issues](https://img.shields.io/github/issues-search/open-telemetry/opentelemetry-collector-contrib?query=is%3Aissue%20is%3Aopen%20label%3Aexporter%2Fclickhouse%20&label=open&color=orange&logo=opentelemetry)](https://github.com/open-telemetry/opentelemetry-collector-contrib/issues?q=is%3Aopen+is%3Aissue+label%3Aexporter%2Fclickhouse) [![Closed issues](https://img.shields.io/github/issues-search/open-telemetry/opentelemetry-collector-contrib?query=is%3Aissue%20is%3Aclosed%20label%3Aexporter%2Fclickhouse%20&label=closed&color=blue&logo=opentelemetry)](https://github.com/open-telemetry/opentelemetry-collector-contrib/issues?q=is%3Aclosed+is%3Aissue+label%3Aexporter%2Fclickhouse) |
 | [Code Owners](https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/CONTRIBUTING.md#becoming-a-code-owner)    | [@hanjm](https://www.github.com/hanjm), [@dmitryax](https://www.github.com/dmitryax), [@Frapschen](https://www.github.com/Frapschen), [@SpencerTorres](https://www.github.com/SpencerTorres) |

exporter/clickhouseexporter/metadata.yaml

@@ -3,8 +3,8 @@ type: clickhouse
 status:
   class: exporter
   stability:
-    alpha: [traces, metrics]
-    beta: [logs]
+    alpha: [metrics]
+    beta: [traces, logs]
   distributions: [contrib]
   codeowners:
     active: [hanjm, dmitryax, Frapschen, SpencerTorres]