TRSS query should not have _xl in the plfatform

TKG queries TRSS for test execution time. The platform for `aarch64_mac` should not have `_xl`

```
00:02:11.422 Attempting to get test duration data from TRSS.
00:02:11.422 curl --silent --max-time 120 https://trssrtp1.fyre.ibm.com/api/getTestAvgDuration?limit=10&jdkVersion=11&impl=j9&platform=aarch64_mac_xl&group=functional&level=sanity
```

[aarch64_mac test build](https://hyc-runtimes-jenkins.swg-devops.com/job/Test_openjdk11_j9_sanity.functional_aarch64_mac/486/console)
[x86-64_mac test build](https://hyc-runtimes-jenkins.swg-devops.com/job/Test_openjdk11_j9_sanity.functional_x86-64_mac/731/console) is correct.

source code: https://github.com/adoptium/TKG/blob/3ed8f8b66bc5ca5906e07efc7adf8abd74abe8fa/src/org/testKitGen/TestDivider.java#L228

Open src/org/testKitGen/TestDivider.java around line 228 and inspect how the TRSS platform query is formed. Compare the aarch64_mac and x86-64_mac test build links, then verify that the generated request uses aarch64_mac without the _xl suffix.

Written by the indexing model from the issue text.