Speculative Flag inaccurate on Configuration Version List

[straubt1]

Description

When Listing Configuration Versions, the Speculative flag was always returning false.
It appears this was due to a trailing space in the struct.

go-tfe version 1.3.0

This change removes that space and allows the function call to return accurately if the CV is speculative.

Testing plan

To replicate, create a CV that is marked as speculative, then list CV's for that workspace.

	cv, err := client.ConfigurationVersions.List(ctx, w.ID, &tfe.ConfigurationVersionListOptions{
		ListOptions: tfe.ListOptions{PageSize: 100},
		Include:     []tfe.ConfigVerIncludeOpt{},
	})

The resulting cv variable will not be marked as Speculative.

[sebasslash]

Good catch 👍 . Approved !

[sebasslash]

🏇 💨

[github-actions]

Reminder to the contributor that merged this PR: if your changes have added important functionality or fixed a relevant bug, open a follow-up PR to update CHANGELOG.md with a note on your changes.