GH-55275: [C++][FlightRPC][ODBC] Unset CPACK_WIX_PRODUCT_GUID to allow Windows installer upgrade (#55276)

### Rationale for this change
GH-55275

https://cmake.org/cmake/help/v4.5/cpack_gen/wix.html#variable:CPACK_WIX_PRODUCT_GUID

> CPACK_WIX_PRODUCT_GUID
> Product GUID (`Product/@ Id`)
> 
> Will be automatically generated unless explicitly provided.
> 
> If explicitly provided this will set the Product Id of your installer.
> 
> The installer **will abort** if it detects a pre-existing installation that uses the **same GUID**.

Highlights my own. 

### What changes are included in this PR?
Removed hard-coded `CPACK_WIX_PRODUCT_GUID`. Then CPack will generate the UUID value for Product ID during each build, and it should unblock users from upgrading using ODBC installer. 

### Are these changes tested?
Regression tested in CI.
Tested installer on local Windows machine and was able to upgrade. 

### Are there any user-facing changes?
no

### Was AI used for this PR?

In accordance to the [AI generation guidelines](https://arrow.apache.org/docs/dev/developers/overview.html#ai-generated-code), please disclose below whether and how AI was used in this PR.

**PR code and description written by:**

- [x] Human
- [x] AI

**Reviewed before submission by:**

- [x] Human
- [x] AI
- [ ] Not reviewed

* GitHub Issue: #55275

Authored-by: Alina (Xi) Li <96995091+alinaliBQ@users.noreply.github.com>
Signed-off-by: David Li <li.davidm96@gmail.com>

cpp/src/arrow/flight/sql/odbc/CMakeLists.txt

@@ -247,7 +247,6 @@ if(ARROW_FLIGHT_SQL_ODBC_INSTALLER)
 
     # Upgrade GUID is required to be unchanged for ODBC installer to upgrade
     set(CPACK_WIX_UPGRADE_GUID "DBF27A18-F8BF-423F-9E3A-957414D52C4B")
-    set(CPACK_WIX_PRODUCT_GUID "279D087B-93B5-4DC3-BA69-BCF485022A26")
   elseif(APPLE)
     # macOS and Linux
     set(CPACK_GENERATOR "productbuild")