release-20.1: acceptance: skip TestDockerCLI/test_demo_partitioning

[thoszhang]

Backport 1/1 commits from #51000.

/cc @cockroachdb/release

---

See: #50970

Release note: None

[cockroach-teamcity]

This change is 

[thoszhang]

We're getting lots of failures on release-20.1:

.201223 21:55:30.837942271 EXPECT TEST: START TEST: Expect partitioning succeeds
spawn /cockroach/cockroach demo --geo-partitioned-replicas
#
# --geo-partitioned replicas operates on a 9 node cluster.
# The cluster size has been changed from the default to 9 nodes.
#
# Welcome to the CockroachDB demo database!
#
# You are connected to a temporary, in-memory CockroachDB cluster of 9 nodes.
#
# This demo session will attempt to enable enterprise features
# by acquiring a temporary license from Cockroach Labs in the background.
# To disable this behavior, set the environment variable
# COCKROACH_SKIP_ENABLING_DIAGNOSTIC_REPORTING=true.
#
# Beginning initialization of the movr dataset, please wait...
#
# Waiting for license acquisition to complete...

error while contacting licensing server:
Get https://register.cockroachdb.com/api/license?clusterid=da500c93-8367-4dad-8a8a-c1965765a635&kind=demo&version=v20.1: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
*
* ERROR: unable to acquire a license for this demo
*
ERROR: unable to acquire a license for this demo
DETAIL: Enterprise features are needed for this demo (--geo-partitioned-replicas).
Failed running "demo"
expect: spawn id exp3 not open
    while executing
"expect {
	$text {}
	timeout { handle_timeout $text }
    }"
    (procedure "eexpect" line 2)
    invoked from within
"eexpect "movr>""
    (file "/go/src/github.com/cockroachdb/cockroach/cli/interactive_tests/test_demo_partitioning.tcl" line 27)
non-zero exit code: 1