Recently, documentation on Synapse has been changed from .rst to .md. Therefore, the current links for the purge history API were resulting in a 404 error.

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/1154

According to
https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy,
having both a header and the `<meta>`-tag provided by Element itself is
not a problem. The 2 CSP policies get combined.

Updating to latest synapse release (performance regression)

https://github.com/matrix-org/synapse/releases/tag/v1.37.1

postgres minor updates

Update IRC bridge

heisenbridge: fix service name in setup_uninstall.yml

Remove asterisks from configuring-dns.md

These previously denoted optional DNS records but now optional records are a separate table so they are unnecessary.

Update hydrogen main.yml

update to v0.2.0

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/1140

Update prometheus  v2.27.1 -> v2.28.0

Coturn update 4.5.2 -> 4.5.2-r2

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1131

The new one is based on Alpine 3.14, instead of Alpine 3.13.

Add support for CentOS (Stream) 8

according to discussion in channel not needed anymore

Content-Security-Policy For Element Web

Update grafana 8.0.2 -> 8.0.3