Disable flaky tests

[iefremov]

As discussed in slack

Failed Tests:

• RewardsBrowserTest.ActivateSettingsModal (../../brave/components/brave_rewards/browser/test/rewards_browsertest.cc:119) - Intermittent rewards browser tests failure - RewardsBrowserTest.ActivateSettingsModal/RewardsPromotionBrowserTest.PromotionRemovedFromEndpoint #12632
• RewardsBrowserTest.UpholdLimitNoBAT (../../brave/components/brave_rewards/browser/test/rewards_browsertest.cc:397) - "RewardsBrowserTest.UpholdLimitNoBAT" failing CI intermittently #12704
• RewardsContributionBrowserTest.TipUnverifiedPublisher (../../brave/components/brave_rewards/browser/test/rewards_contribution_browsertest.cc:303) - Rewards browser test intermittent failure: RewardsContributionBrowserTest.TipUnverifiedPublisher and RewardsBrowserTest.ResetRewardsWithBAT #12607
• RewardsPromotionBrowserTest.PromotionRemovedFromEndpoint (../../brave/components/brave_rewards/browser/test/rewards_promotion_browsertest.cc:230) - Intermittent rewards browser tests failure - RewardsBrowserTest.ActivateSettingsModal/RewardsPromotionBrowserTest.PromotionRemovedFromEndpoint #12632
• RewardsContributionBrowserTest.TipConnectedPublisherVerified (../../brave/components/brave_rewards/browser/test/rewards_contribution_browsertest.cc:585) - "RewardsContributionBrowserTest.TipConnectedPublisherVerified" failing CI intermittently #12985
• RewardsPublisherBrowserTest.PanelShowsCorrectPublisherData (../../brave/components/brave_rewards/browser/test/rewards_publisher_browsertest.cc:100) - "RewardsPublisherBrowserTest.PanelShowsCorrectPublisherData" failing CI intermittently #12986
  Timeout Tests:
• RewardsBrowserTest.BackupRestoreModalHasNotice (../../brave/components/brave_rewards/browser/test/rewards_browsertest.cc:303) - "RewardsBrowserTest.BackupRestoreModalHasNotice" timeout CI intermittently #12987
• RewardsBrowserTest.ResetRewardsWithBAT (../../brave/components/brave_rewards/browser/test/rewards_browsertest.cc:374) - Rewards browser test intermittent failure: RewardsContributionBrowserTest.TipUnverifiedPublisher and RewardsBrowserTest.ResetRewardsWithBAT #12607
• RewardsPromotionBrowserTest.ClaimViaSettingsPage (../../brave/components/brave_rewards/browser/test/rewards_promotion_browsertest.cc:195) - Intermittent rewards browser test failure: RewardsPromotionBrowserTest.ClaimViaPanel and RewardsPromotionBrowserTest.ClaimViaSettingsPage #12605
  Crash Tests:
• RewardsBrowserTest.ToggleAutoContribute (../../brave/components/brave_rewards/browser/test/rewards_browsertest.cc:130) - "RewardsBrowserTest.ToggleAutoContribute" crashes CI intermittently #12988