Render changelog sections only if they contain content

[amoghrajesh]

While categorising PRs for providers, if a section didn't have any content, empty headers were rendered. This PR makes that content conditional.

Example output:

NEXT VERSION AFTER + 8.1.2
..........................

Latest change: 2024-06-27

=================================================================================================  ===========  ===========================================================
Commit                                                                                             Committed    Subject
=================================================================================================  ===========  ===========================================================
`a62bd83188 <https://github.com/apache/airflow/commit/a62bd831885957c55b073bf309bc59a1d505e8fb>`_  2024-06-27   ``Enable enforcing pydocstyle rule D213 in ruff. (#40448)``
=================================================================================================  ===========  ===========================================================

Does the provider: apache.hive have any changes apart from 'doc-only'?
Press y/N/q: y

Define the type of change for `Enable enforcing pydocstyle rule D213 in ruff. (https://github.com/apache/airflow/pull/40448)` by referring to the above table
Type of change (b)ugfix, (f)eature, (x)breaking change, (m)misc, (s)kip, (q)uit ? x

The version will be bumped because of TypeOfChange.BREAKING_CHANGE kind of change
Provider apache.hive has been classified as:

Breaking changes - bump in MAJOR version needed

Bumped version to 9.0.0

Updated source-date-epoch to 1720505379

New version of the 'apache.hive' package is ready to be released!


Do you want to leave the version for apache.hive with version: 9.0.0 as is for the release?
Press y/N/q: y
 Proceeding with provider: apache.hive version as 9.0.0
Checking for backticks correctly generated in: /Users/adesai/Documents/OSS/airflow/docs/apache-airflow-providers-apache-hive/changelog.rst
Generated /Users/adesai/Documents/OSS/airflow/docs/apache-airflow-providers-apache-hive/changelog.rst for apache.hive is OK

Generated /Users/adesai/Documents/OSS/airflow/docs/apache-airflow-providers-apache-hive/commits.rst file for the apache.hive provider

36a37,47
>
> 9.0.0
> .....
>
> Latest change: 2024-06-27
>
> =================================================================================================  ===========  ===========================================================
> Commit                                                                                             Committed    Subject
> =================================================================================================  ===========  ===========================================================
> `a62bd83188 <https://github.com/apache/airflow/commit/a62bd831885957c55b073bf309bc59a1d505e8fb>`_  2024-06-27   ``Enable enforcing pydocstyle rule D213 in ruff. (#40448)``
> =================================================================================================  ===========  ===========================================================
41c52
< Latest change: 2024-06-17
---
> Latest change: 2024-06-22
45a57
> `6e5ae26382 <https://github.com/apache/airflow/commit/6e5ae26382b328e88907e8301d4b2352ef8524c5>`_  2024-06-22   ``Prepare docs 2nd wave June 2024 (#40273)``
Checking for backticks correctly generated in: /Users/adesai/Documents/OSS/airflow/docs/apache-airflow-providers-apache-hive/commits.rst
Generated /Users/adesai/Documents/OSS/airflow/docs/apache-airflow-providers-apache-hive/commits.rst for apache.hive is OK

Updates changelog for last release of package 'apache.hive'

New version of the 'apache.hive' package is ready to be released!

***

---

***************

*** 24,33 ****

--- 24,45 ----

  ``apache-airflow-providers-apache-hive``


  Changelog
  ---------
+
+ 9.0.0
+ .....
+
+ Breaking changes
+ ~~~~~~~~~~~~~~~~
+
+ * ``Enable enforcing pydocstyle rule D213 in ruff. (#40448)``
+
+
+ .. Below changes are excluded from the changelog. Move them to
+    appropriate section above if needed. Do not delete the lines(!):

  8.1.2
  .....

  Misc
The provider apache.hive changelog for `9.0.0` version is missing. Generating fresh changelog.

Update index.rst for apache.hive


Generated /Users/adesai/Documents/OSS/airflow/docs/apache-airflow-providers-apache-hive/index.rst file for the apache.hive provider

82c82
< Release: 8.1.2
---
> Release: 9.0.0
146,147c146,147
< * `The apache-airflow-providers-apache-hive 8.1.2 sdist package <https://downloads.apache.org/airflow/providers/apache_airflow_providers_apache_hive-8.1.2.tar.gz>`_ (`asc <https://downloads.apache.org/airflow/providers/apache_airflow_providers_apache_hive-8.1.2.tar.gz.asc>`__, `sha512 <https://downloads.apache.org/airflow/providers/apache_airflow_providers_apache_hive-8.1.2.tar.gz.sha512>`__)
< * `The apache-airflow-providers-apache-hive 8.1.2 wheel package <https://downloads.apache.org/airflow/providers/apache_airflow_providers_apache_hive-8.1.2-py3-none-any.whl>`_ (`asc <https://downloads.apache.org/airflow/providers/apache_airflow_providers_apache_hive-8.1.2-py3-none-any.whl.asc>`__, `sha512 <https://downloads.apache.org/airflow/providers/apache_airflow_providers_apache_hive-8.1.2-py3-none-any.whl.sha512>`__)
---
> * `The apache-airflow-providers-apache-hive 9.0.0 sdist package <https://downloads.apache.org/airflow/providers/apache_airflow_providers_apache_hive-9.0.0.tar.gz>`_ (`asc <https://downloads.apache.org/airflow/providers/apache_airflow_providers_apache_hive-9.0.0.tar.gz.asc>`__, `sha512 <https://downloads.apache.org/airflow/providers/apache_airflow_providers_apache_hive-9.0.0.tar.gz.sha512>`__)
> * `The apache-airflow-providers-apache-hive 9.0.0 wheel package <https://downloads.apache.org/airflow/providers/apache_airflow_providers_apache_hive-9.0.0-py3-none-any.whl>`_ (`asc <https://downloads.apache.org/airflow/providers/apache_airflow_providers_apache_hive-9.0.0-py3-none-any.whl.asc>`__, `sha512 <https://downloads.apache.org/airflow/providers/apache_airflow_providers_apache_hive-9.0.0-py3-none-any.whl.sha512>`__)


Summary of prepared documentation:

Success: 1

apache.hive


Successfully prepared documentation for packages!



Please review the updated files, classify the changelog entries and commit the changes.

---

^ Add meaningful description above
Read the Pull Request Guidelines for more information.
In case of fundamental code changes, an Airflow Improvement Proposal (AIP) is needed.
In case of a new dependency, check compliance with the ASF 3rd Party License Policy.
In case of backwards incompatible changes please leave a note in a newsfragment file, named {pr_number}.significant.rst or {issue_number}.significant.rst, in newsfragments.

[amoghrajesh]

I had seen this issue for quite some time, its quite annoying to delete these sections manually.
cc @eladkal @potiuk

[potiuk]

Oh yeah - it makes sense now when we classification of changes is done before generating the docs. Good call @amoghrajesh :)