Removing WEBSITE_CONTAINER_READY=0 env variable check for DotnetIsolatedLinuxPlaceholder profile

[kshyju]

In this PR, we added a profile condition to check if the environment variable WEBSITE_CONTAINER_READY is set to 0, following our wiki page. However, testing revealed this does not work, as the flex SKU did not set this environment variable. The Linux team conducted an initial investigation to find the impact of adding this environment variable to the container but found that other parts of the system expect this value to be not null rather than checking for a specific value (1). We have decided to remove this environment variable check, understanding the impact of this change.

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