Keyless Azure Auth in test-linux

[reakaleek]

Use OIDC to login to azure.

[reakaleek]

I will disable the azure-tests job again.

But I was able to validate that the OIDC login works and terraform resources are created as expected in https:/elastic/apm-agent-dotnet/actions/runs/9700716496/job/26773022726

P.S. I found many tests failing after a timeout of 15 minutes..

Maybe we want to increase:

apm-agent-dotnet/test/Elastic.Apm.Tests.Utilities/Terraform/TerraformResources.cs

Line 24 in e646ef8

private static readonly TimeSpan _defaultTimeout = TimeSpan.FromMinutes(15);

In Terraform, the delete timeout is actually set to 180 minutes. So I suspect that it needs more time. Source: https://registry.terraform.io/providers/hashicorp/azurerm/latest/docs/resources/cosmosdb_account#timeouts