Assertions are no longer logged or detected in the default scenario

### Issue

The assertion detecting logic in PMIDriver (https://github.com/dotnet/jitutils/blob/945715f07ce9c4381b3ab199f2cd52b586a89415/src/pmi/PMIDriver.cs#L214-L267) is no longer correct for what the JIT currently outputs.

Additionally, due to other changes in the JIT, assertions are never logged in the default scenario.

### Repro

1. Clone dotnet/runtime
2. Build the repo in all required configurations
3. Clone dotnet/jitutils
4. Build the repo using `.\bootstrap.cmd`
5. In the dotnet/runtime root, run `jit-diff.bat diff --diff --pmi`

Observe that the command fails due to https://github.com/dotnet/runtime/issues/51728. However, `System.Private.Corelib.err` reports: `General error, no assert seen.`

### Analysis

`assertAbort` (https://github.com/dotnet/runtime/blob/main/src/coreclr/jit/error.cpp#L277-L323) currently fails to log anything because `COMPlus_JitFuncInfoLogFile` is not set and because the default `CoreCLR.dll` (VM) for the PMI diffs is `release` which means `CEEInfo::doAssert` does not actually print anything: https://github.com/dotnet/runtime/blob/main/src/coreclr/vm/jitinterface.cpp#L10897-L10925

Additionally, even if the assertions are printed, they currently resemble:
```
Encoding:GetCharsWithFallback(long,int,long,int,int,int):int:this - Assertion failed (C:\Users\tagoo\Source\repos\runtime_base\src\coreclr\jit\emitxarch.cpp:11739 - ((regMask & emitThisGCrefRegs) && (ins == INS_add)) || ((regMask & emitThisByrefRegs) && (ins == INS_add || ins == INS_sub))) during Emit code
```

While the PMIDriver is currently looking for `]): Assertion failed '` and `Assert failure(PID `, neither of which are used by this failure path.