Update knative instructions

[dievskiy]

Explanation

This PR fixes minor issues with the current knative setup guide. The update is needed to follow the instructions without the issues.

Related issue

N/A

What type of PR is this

/kind bug
/kind documentation

Proposed Changes

Fix minor issues

[alabulei1]

Hello, I am a code review bot on flows.network. Here are my reviews of code commits in this PR.

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Commit 558819b22492834b90f46761676189a7ab4ad251

Key Changes:

1. Removed redundant export of KUBECONFIG, as it was previously set before applying the runtime.yaml file.
2. Updated the command for applying the runtime.yaml file to use the -f flag, providing the filename explicitly.
3. Corrected the command for applying the http-wasm-serverless.yaml file to use the -f flag, providing the filename explicitly.

Potential Problems:

1. The redundant export of KUBECONFIG was removed, which seems like a good cleanup. No issues here.
2. The command for applying the runtime.yaml file was corrected to use the -f flag; this is a necessary change to ensure the correct file is applied.
3. The command for applying the http-wasm-serverless.yaml file was also corrected to use the -f flag; this correction is important to avoid errors in applying the file.

Overall, these changes seem beneficial and necessary for updating the Knative instructions. The changes appear to be focused on improving the clarity and correctness of the deployment instructions.

[alabulei1]

Hi @dievskiy

Thanks for your contribution. Could you please fix the DCO CI first?

[dievskiy]

Should be fine now.