Remove redundant jars and conditions when Hybrid 1.5 support drops

[rockspore]

The current version checking has a flaw in that it can't work well when the minor version reaches two digits. This should be still far away from now but we should be able to stop relying on the version check to select a particular products callout jar once Hybrid 1.5 is not supported by Apigee any more.

[rockspore]

1.5 and even 1.6 are not supported Hybrid version any more (evidence: https://cloud.google.com/apigee/docs/hybrid/supported-platforms). I think it's time to get rid of this time bomb.
@theganyo @emschwar

[rockspore]

apigee-remote-service-cli/cmd/provision/proxies/remote-service-gcp/apiproxy/proxies/default.xml

Lines 90 to 100 in 0556dc4

	<Step>
	<Name>Get-Runtime-Version</Name>
	</Step>
	<Step>
	<Name>Legacy-Products-Callout</Name>
	<Condition>(lookupcache.Lookup-Products.cachehit = false) and (runtime_version LesserThan "1.5.0")</Condition>
	</Step>
	<Step>
	<Name>Products-Callout</Name>
	<Condition>(lookupcache.Lookup-Products.cachehit = false) and (runtime_version GreaterThanOrEquals "1.5.0"</Condition>
	</Step>

is the condition that needs to be cleaned up.

https://github.com/apigee/apigee-remote-service-cli/blob/main/cmd/provision/proxies/remote-service-gcp/apiproxy/resources/py/get-runtime-version.py will eventually stop working properly once the minor version reaches double-digit. But this is not harmful as long as it's not used in critical places like above.