Fail fast in tests if avalancheGo executable isn't an absolute path

[yacovm]

How this works

Currently when running ginkgo tests with --avalanchego flag with a relative path, the tests fail when trying to ascertain the rpcvm plugin path, because they execute the binary without an absolute path, and the binary path is evaluated from a wrong location.

In order to make the underlying issue clear, I added a check that fails the test and warns that an absolute path must be used.

Why this should be merged

Checks if the path is relative and if so, fails fast with an error.

How this was tested

ran it locally:

➜  avalanchego git:(absolutePath) ginkgo -v --focus-file=faultinjection/duplicate_node_id.go  ./tests/e2e -- --avalanchego-path=./build/avalanchego        
Running Suite: e2e test suites - /Users/yacov.manevich/avalanchego/tests/e2e
============================================================================
Random Seed: 1738883202

Will run 1 of 13 specs
------------------------------
[SynchronizedBeforeSuite] 
/Users/yacov.manevich/avalanchego/tests/e2e/e2e_test.go:34
  [FAILED] in [SynchronizedBeforeSuite] - /Users/yacov.manevich/go/pkg/mod/github.com/stretchr/[email protected]/assert/assertions.go:1545 @ 02/07/25 00:06:52.681
[SynchronizedBeforeSuite] [FAILED] [0.023 seconds]
[SynchronizedBeforeSuite] 
/Users/yacov.manevich/avalanchego/tests/e2e/e2e_test.go:34

  [FAILED] 
        Error Trace:    /Users/yacov.manevich/avalanchego/tests/fixture/e2e/env.go:137
                                                /Users/yacov.manevich/avalanchego/tests/e2e/e2e_test.go:39
                                                /Users/yacov.manevich/go/pkg/mod/golang.org/[email protected]/src/reflect/value.go:596
                                                /Users/yacov.manevich/go/pkg/mod/golang.org/[email protected]/src/reflect/value.go:380
                                                /Users/yacov.manevich/go/pkg/mod/github.com/onsi/ginkgo/[email protected]/internal/node.go:486
                                                /Users/yacov.manevich/go/pkg/mod/github.com/onsi/ginkgo/[email protected]/internal/suite.go:642
                                                /Users/yacov.manevich/go/pkg/mod/github.com/onsi/ginkgo/[email protected]/internal/suite.go:889
                                                /Users/yacov.manevich/go/pkg/mod/golang.org/[email protected]/src/runtime/asm_amd64.s:1695
        Error:          Received unexpected error:
                        avalanchego-path (./build/avalanchego) is a relative path but must be an absolute path
  
  In [SynchronizedBeforeSuite] at: /Users/yacov.manevich/go/pkg/mod/github.com/stretchr/[email protected]/assert/assertions.go:1545 @ 02/07/25 00:06:52.681

Need to be documented in RELEASES.md?

No