Remove extra "=" on virtctl_client_tool user_guide

[gcezaralmeida]

What this PR does / why we need it: There is a typo on the virtctl Client Tool installation, this extra "=" is leading users to an error when trying to install virtctl.

galmeida@VAN-932852-LT0:~/kubevirt-gitops$ export VERSION==$(curl https://storage.googleapis.com/kubevirt-prow/release/kubevirt/kubevirt/stable.txt)
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100     7  100     7    0     0     89      0 --:--:-- --:--:-- --:--:--    89
galmeida@VAN-932852-LT0:~/kubevirt-gitops$ wget https://github.com/kubevirt/kubevirt/releases/download/${VERSION}/virtctl-${VERSION}-linux-amd64
--2024-04-25 11:24:35--  https://github.com/kubevirt/kubevirt/releases/download/=v1.2.0/virtctl-=v1.2.0-linux-amd64
Resolving github.com (github.com)... 140.82.114.4
Connecting to github.com (github.com)|140.82.114.4|:443... connected.
HTTP request sent, awaiting response... 404 Not Found
2024-04-25 11:24:36 ERROR 404: Not Found.

galmeida@VAN-932852-LT0:~/kubevirt-gitops$ echo $VERSION
=v1.2.0

E.g. Expected --> v1.2.0 Actual result --> =v1.2.0

Special notes for your reviewer: This is my first PR, sorry about any mistakes.

Checklist

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• [ ] Design: A design document was considered and is present (link) or not required
• [ ] PR: The PR description is expressive enough and will help future contributors
• [ ] Code: Write code that humans can understand and Keep it simple
• [ ] Refactor: You have left the code cleaner than you found it (Boy Scout Rule)
• [ ] Upgrade: Impact of this change on upgrade flows was considered and addressed if required
• [ ] Testing: New code requires new unit tests. New features and bug fixes require at least on e2e test
• [ ] Documentation: A user-guide update was considered and is present (link) or not required. You want a user-guide update if it's a user facing feature / API change.
• [ ] Community: Announcement to kubevirt-dev was considered

Release note:

[kubevirt-bot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: Once this PR has been reviewed and has the lgtm label, please assign mhenriks for approval. For more information see the Kubernetes Code Review Process.

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Needs approval from an approver in each of these files: - **[OWNERS](https://github.com/kubevirt/user-guide/blob/main/OWNERS)** Approvers can indicate their approval by writing `/approve` in a comment Approvers can cancel approval by writing `/approve cancel` in a comment

[kubevirt-bot]

Hi @gcezaralmeida. Thanks for your PR.

I'm waiting for a kubevirt member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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