Coverage report returns empty string after Simnet re-initialization

[BowTiedRadone]

Describe the Bug
When trying to get a coverage report on a Simnet session that was re-initialized using initEmptySession, the report returns an empty string. While Simnet sessions can be re-initialized, this issue occurs specifically when retrieving the coverage report after re-initialization.

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To Reproduce Steps to reproduce the issue:

1. Create a new Clarinet project:

   clarinet new demo
   

2. Add a new contract:

   clarinet contract new hi
   

3. Replace the content of contracts/hi.clar with:

   (define-public (say-hi)
     (ok true)
   )
   

4. Create a minimal index.js in the project with this code:

   import { initSimnet } from "@hirosystems/clarinet-sdk";
   
   const main = async () => {
     const simnet = await initSimnet("Clarinet.toml", false, {
       trackCosts: false,
       trackCoverage: true,
     });
   
     await simnet.initEmptySession();
     simnet.setEpoch("2.5");
     simnet.deployContract(
       "hi",
       `(define-public (say-hello) (ok true))`,
       { clarityVersion: 2 },
       simnet.deployer
     );
   
     simnet.callPublicFn(
       `${simnet.deployer}.hi`,
       "say-hello",
       [],
       simnet.deployer
     );
   
     const report = simnet.collectReport(false, "");
     console.log("coverage:", report.coverage);
   };
   
   await main();
   

5. Run the code:

   node index.js
   

6. Check the output:

   coverage:  // empty string
   

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Expected Behavior
The coverage report should contain data for the updated contract source instead of being empty.

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Environment

• OS: macOS 14.6.1
• Clarinet version: 2.12.0