[E2E] Fixing the error for File variables for workspace_actions_spec

What does this MR do and why?

There are failures related to these CI variable, where the variable is passed in to a helm command, so there is error saying no such file. So breaking it down to figure out if the command inside command was causing the issue.

cat: /builds/gitlab-org/quality/staging.tmp/WORKSPACES_DOMAIN_CERT: No such file or directory
cat: /builds/gitlab-org/quality/staging.tmp/WORKSPACES_DOMAIN_KEY: No such file or directory
cat: /builds/gitlab-org/quality/staging.tmp/WORKSPACES_WILDCARD_CERT: No such file or directory
cat: /builds/gitlab-org/quality/staging.tmp/WORKSPACES_WILDCARD_KEY: No such file or directory

Based on changes in gitlab-qa!1233 (merged), this MR should be merged after this

Related to https://gitlab.com/gitlab-org/gitlab/-/issues/424857

How to set up and validate locally

The full list of variable and their values to run this spec can be found in 1password "Run workspaces tests against staging"

bundle exec bin/qa Test::Instance::All https://staging.gitlab.com -- -- qa/specs/features/ee/browser_ui/3_create/remote_development/workspace_actions_spec.rb

MR acceptance checklist

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