Spec test coverage report hack (#13718)

* Spec test report hack

* no export

* fix shell complaint

* shell fix?

* shell again?

* chmod +x ./hack/spectest-report.sh

* Review + improvements

* Remove unwanted change

* Add exclusion list

* Fix path + add eip6110 to exclusion

* Fix bazel path nonsense

* Add extra detail about specific test

* Cleanup exclusion list

* Add fail conditions

* Add mkdir

* Shorten filename + mkdir only if new

* Fix names

* Add to exclusion list

* Add report to .gitignore

* Back to stupid names

* Add Bazel flags option

---------

Co-authored-by: Preston Van Loon <pvanloon@offchainlabs.com>

.gitignore

@@ -41,3 +41,6 @@ jwt.hex
 
 # manual testing
 tmp
+
+# spectest coverage reports
+report.txt