test/extended/cli/adm_upgrade/recommend: Handle accepted Upgradeable=False

In 44cd78a (test/extended/cli/adm_upgrade/recommend: Account for
Upgradeable=False, 2025-08-05, #30113), I'd updated the regular
expression to accept:

  Reason: MultipleReasons

for clusters that had both Upgradeable=False and conditional risks
going on.  In 7724a75 (test/extended/cli/adm_upgrade/recommend:
Trust the ingress CA, 2025-08-14, #30113), I extended the regular
expression to cover:

  Reason: accepted TestRiskA via ConditionalUpdateRisk

But I hadn't thought through the MultipleReasons case, and this commit
catches us up to tech-preview serial output like [1]:

  ...
  Reason: accepted MultipleReasons via ConditionalUpdateRisk
  Message: Cluster operator config-operator should not be upgraded between minor versions: FeatureGatesUpgradeable: "TechPreviewNoUpgrade" does not allow updates

    This is a test risk. https://example.com/testRiskA
  ...

[1]: https://prow.ci.openshift.org/view/gs/test-platform-results/pr-logs/pull/30113/pull-ci-openshift-origin-main-e2e-gcp-ovn-techpreview-serial-1of2/1963672599955247104

Author: wking

test/extended/cli/adm_upgrade/recommend.go

@@ -251,7 +251,7 @@ Channel: test-channel [(]available channels: other-channel, test-channel[)]
 Update to 4[.][0-9]*[.]0 Recommended=False:
 Image: example.com/test@sha256:cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
 Release URL: https://example.com/release/4[.][0-9]*[.]0
-Reason: (accepted TestRiskA via ConditionalUpdateRisk|MultipleReasons)
+Reason: accepted (TestRiskA|MultipleReasons) via ConditionalUpdateRisk
 Message: (?s:.*)This is a test risk[.] https://example.com/testRiskA
 Update to 4[.][0-9]*[.]0 has no known issues relevant to this cluster other than the accepted ConditionalUpdateRisk.`)
 				o.Expect(err).NotTo(o.HaveOccurred())