[kube-stack] Bump opentelemetry-operator chart to 0.71

[rogercoll]

Generated examples with: make generate-examples CHARTS=opentelemetry-kube-stack

This will fix an issue when using the Helm Chart with a collector's image > 0.110.0:

$ k logs -n opentelemetry-operator-system opentelemetry-kube-stack-daemon-collector-xggww                          
invalid argument "-component.UseLocalHostAsDefaultHost" for "--feature-gates" flag: feature gate "component.UseLocalHostAsDefaultHost" is stable, can not be disabled

[rogercoll]

Example configuration:

defaultCRConfig:
  image:
    repository: "otel/opentelemetry-collector-k8s"
    tag: "0.110.0"

[rogercoll]

Feature gate was removed in Operator's v0.110.0: https://github.com/open-telemetry/opentelemetry-operator/pull/3336/files#diff-06572a96a58dc510037d5efa622f9bec8519bc1beab13c9f251e97e657a9d4edR28

[jaronoff97]

two minor things, thank you!

[rogercoll]

@jaronoff97 I had to bump the Python version used in the CI as it seems 3.7 was removed from the used runners:

  Version 3.7 was not found in the local cache
  Error: The version '3.7' with architecture 'x64' was not found for Ubuntu 24.04.
  The list of all available versions can be found here: https://raw.githubusercontent.com/actions/python-versions/main/versions-manifest.json