Changes

docs PDF: add release-8.2 and remove archived versions (#3020)

### **PR Type**
configuration changes


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### **Description**
- Updated branch patterns in `docs-cn-postsubmits.yaml` and
`docs-postsubmits.yaml` to include support for `release-8.2`.
- Removed support for `release-5.0` and `release-6.6` in both files.



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### **Changes walkthrough** 📝
<table><thead><tr><th></th><th align="left">Relevant
files</th></tr></thead><tbody><tr><td><strong>Configuration
changes</strong></td><td><table>
<tr>
  <td>
    <details>
<summary><strong>docs-cn-postsubmits.yaml</strong><dd><code>Update
branch patterns for docs-cn postsubmits</code>&nbsp; &nbsp; &nbsp;
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </dd></summary>
<hr>
      
prow-jobs/pingcap/docs/docs-cn-postsubmits.yaml

<li>Updated branch patterns for postsubmits.<br> <li> Added support for
<code>release-8.2</code>.<br> <li> Removed support for
<code>release-5.0</code> and <code>release-6.6</code>.<br>


</details>
    

  </td>
<td><a
href="https://github.com/PingCAP-QE/ci/pull/3020/files#diff-a8bd1b126b4211a56553a1a30b5216df53edaba89d5a577790b6832288b489e4">+4/-4</a>&nbsp;
&nbsp; &nbsp; </td>

</tr>                    

<tr>
  <td>
    <details>
<summary><strong>docs-postsubmits.yaml</strong><dd><code>Update branch
patterns for docs postsubmits</code>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;
</dd></summary>
<hr>
      
prow-jobs/pingcap/docs/docs-postsubmits.yaml

<li>Updated branch patterns for postsubmits.<br> <li> Added support for
<code>release-8.2</code>.<br> <li> Removed support for
<code>release-5.0</code> and <code>release-6.6</code>.<br>


</details>
    

  </td>
<td><a
href="https://github.com/PingCAP-QE/ci/pull/3020/files#diff-b1066d5a5f50efe588f78cadcc9c9441d11c1b017c00a85627e2af77af140bf7">+4/-4</a>&nbsp;
&nbsp; &nbsp; </td>

</tr>                    
</table></td></tr></tr></tbody></table>

___

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Co-authored-by: wuhuizuo <wuhuizuo@126.com>
 (commit: e9f5fd4)