Remove global changelog entries moved to collection changelogs

[felixfontein]

Will clean up entries when the following PRs are merged:

• Add porting guide entries from Ansible-base porting guide ansible-collections/community.general#703 (merged in Link to porting guides and mention date in release summary #25)
• Add porting guide entries from Ansible-base porting guide ansible-collections/community.vmware#325 (merged in Reduce changelog for AWS and vmware collections #30)
• Add porting guide entries from Ansible-base porting guide ansible-collections/ansible.windows#85
• Add porting guide entries from Ansible-base porting guide ansible-collections/community.windows#119, Porting guide: forgot second part ansible-collections/community.windows#121
• Add porting guide entries from Ansible-base porting guide ansible-collections/amazon.aws#118 (merged in Reduce changelog for AWS and vmware collections #30)
• Add porting guide entries from Ansible-base porting guide ansible-collections/community.aws#165 (merged in Reduce changelog for AWS and vmware collections #30)

[felixfontein]

Once the Windows collections have been re-released, we can also merge this one.

[felixfontein]

The Windows collections have been released as 1.0.0 (ansible-collections/community.windows#124 and ansible-collections/ansible.windows#88) and will show up in the next alpha. Before we release the alpha, we should merge this, so that the porting guide entries do not appear multiple times.