Add Config Option for Including Environment Variables When Importing/Exporting Chatflow as DSL

[jacktanxd]

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1. Is this request related to a challenge you're experiencing? Tell me about your story.

Function for importing and exporting chatflow as DSL files: suggest adding a configuration option to include environment variables or not. Otherwise, every time a DSL file exported from the test environment is imported into the production environment, all environment variables will be overwritten.

2. Additional context or comments

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• I am interested in contributing to this feature.