fix: Update root CA to ISRG Root X1

[Technoguyfication]

Proposed Changes

The current CA certificate used to trust InfluxCloud servers is DST Root CA X3, this expires September 30th 2021. This change replaces it with the certificate's successor, ISRG Root X1. You can read more about the certificate update here.

Checklist

• CHANGELOG.md updated
• Rebased/mergeable
• Commit messages are in semantic format

[vlastahajek]

@Technoguyfication, thank you for the update of the certificate and readme!

InfluxData has 3 provides for InfluxDBCloud: AWS, Azure, GCP.
This new CA certificate works OK for AWS and Azure, but doesn't work for GCP:

BSSL:_connectSSL: start connection
BSSL:_wait_for_handshake: failed
BSSL:Couldn't connect. Error = 'Chain could not be linked to a trust anchor.'

I checked AWS and GPC , but I don't understand how the AWS certificate is linked to the ISRG Root X1 CA and why the GCP fails.

[vlastahajek]

After giving some time to people maintaining InfluxDB Clouds to update certificates, the new CA certificate is now working for all providers 👍.