test: disable ostree-remount service checking since /sysroot is ro and /var rw already

[mcattamoredhat]

This pull request includes:

Since /sysroot is being mounted as ro and /var as rw, ostree-remount.service will not remount those mountpoints. The test is no longer necessary.
Thus, this PR suggests to delete the task as a workaround for the reported Jira edge-commit CS9 failure: ostree-remount.service fails to remount /sysroot and /var mountpoints

• adequate testing for the new functionality or fixed issue
• adequate documentation informing people about the change such as
  • submit a PR for the READMEs listed here
  • submit a PR for the osbuild.org website repository if this PR changed any behavior not covered by the automatically updated READMEs

[say-paul]

LGTM

[bcl]

Could you update the commit message with the same details you put in the github description? It would make it clear to people looking at the git log as to why this was changed.