[Uplift to 1.4] Don't use cached images for NTP Sponsored images

[simonhong]

When assets are updated, we should display new images always.

Fix brave/brave-browser#8112

[kjozwiak]

Looks like lint is failing on all the platforms as per the following:

• android - https://ci.brave.com/job/brave-browser-build-pr/job/uplift_4539_to_1_4/1/execution/node/378/log/
• iOS - https://ci.brave.com/job/brave-browser-build-pr/job/uplift_4539_to_1_4/1/execution/node/424/log/
• Linux - https://ci.brave.com/job/brave-browser-build-pr/job/uplift_4539_to_1_4/1/execution/node/332/log/
• macOS - https://ci.brave.com/job/brave-browser-build-pr/job/uplift_4539_to_1_4/1/execution/node/284/log/

Looking into the above errors to make these are fine to ignore. Both @yrliou and @petemill confirmed that lint is passing locally and this is only affecting CI.

audit-network failed on both Linux & macOS which is expected as #4527 & brave/brave-browser#8103 hasn't been merged.

• Linux - https://ci.brave.com/job/brave-browser-build-pr/job/uplift_4539_to_1_4/1/execution/node/522/log/
• macOS - https://ci.brave.com/job/brave-browser-build-pr/job/uplift_4539_to_1_4/1/execution/node/615/log/

Both macOS & Win x64 failed on test-install which is a known issue and not related to this specific PR:

• macOS - https://ci.brave.com/job/brave-browser-build-pr/job/uplift_4539_to_1_4/1/execution/node/706/log/
• Win x64 - https://ci.brave.com/job/brave-browser-build-pr/job/uplift_4539_to_1_3/1/execution/node/778/log/

[kjozwiak]

Uplift into 1.4.x approved after deliberating with @brave/uplift-approvers. Failures are all related to audit-network, lint and test-intsall which are known issues and not related to this specific PR.

Please ensure that all the correct labels are being used and the associated issue is moved into the correct milestone.