[Tech Debt] Rename createTestEnvironment to makeSut in 21 test files

[sonikro]

Problem

The project's test conventions (.github/instructions/tests.instructions.md) mandate that the test setup function be named makeSut. However, 21 test files across all packages use createTestEnvironment instead:

packages/entrypoints/src/jobs/ConsumeCreditsRoutine.test.ts
packages/entrypoints/src/jobs/TerminateServersWithoutCreditRoutine.test.ts
packages/entrypoints/src/udp/srcdsCommands/ClientConnected.test.ts
packages/entrypoints/src/udp/srcdsCommands/Say.test.ts
packages/entrypoints/src/udp/srcdsCommands/UserEnteredGame.test.ts
packages/providers/src/services/DiscordEventLogger.test.ts
packages/providers/src/services/AdyenPaymentService.test.ts
packages/providers/src/services/PaypalPaymentService.test.ts
packages/providers/src/cloud-providers/oracle/OCIServerManager.test.ts
packages/providers/src/cloud-providers/oracle/OracleVMManager.test.ts (will be deleted in #266)
packages/core/src/usecase/TerminateServersWithoutCredit.test.ts
packages/core/src/usecase/CreateCreditsPurchaseOrder.test.ts
packages/core/src/usecase/TerminateEmptyServers.test.ts
packages/core/src/usecase/CreateServerForUser.test.ts
packages/core/src/usecase/HandleOrderPaid.test.ts
packages/core/src/usecase/SetUserData.test.ts
packages/core/src/usecase/ConsumeCreditsFromRunningServers.test.ts
packages/core/src/usecase/TerminateLongRunningServers.test.ts
packages/core/src/models/ServerDeploymentResult.test.ts
packages/core/src/models/DeploymentContext.test.ts
packages/core/src/models/ServerCredentials.test.ts

Fix

In each affected file, rename the setup function from createTestEnvironment → makeSut (and update all call sites within the file too).

Note: OracleVMManager.test.ts will be deleted as part of #266 so it doesn't need to be updated.