chore: skip aliasshim for all env (googleapis#11755)

Previously this was only being applied to earliest builds. This is a followup to googleapis#11635.

Author: codyoss

internal/kokoro/continuous.sh

@@ -97,11 +97,13 @@ try3 go mod download
 # runDirectoryTests runs all tests in the current directory.
 # If a PATH argument is specified, it runs `go test [PATH]`.
 runDirectoryTests() {
+  if [[ $PWD == *"/aliasshim" ]]; then
+    # aliasshim: build constraints exclude all Go files
+    return
+  fi
   if { [[ $PWD == *"/internal/"* ]] ||
-    [[ $PWD == *"/third_party/"* ]] ||
-    [[ $PWD == *"/aliasshim" ]]; } &&
+    [[ $PWD == *"/third_party/"* ]]; } &&
     [[ $KOKORO_JOB_NAME == *"earliest"* ]]; then
-    # aliasshim: build constraints exclude all Go files
     # internal tools only expected to work with latest go version
     return
   fi