Fix SeqeraExecutorTest missing SysEnv.push in new tests

The cleanup() method calls SysEnv.pop(), so every test must push first.

Signed-off-by: Paolo Di Tommaso <paolo.ditommaso@gmail.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Signed-off-by: Paolo Di Tommaso <paolo.ditommaso@gmail.com>

Author: pditommaso

plugins/nf-seqera/src/test/io/seqera/executor/SeqeraExecutorTest.groovy

@@ -112,6 +112,7 @@ class SeqeraExecutorTest extends Specification {
 
     def 'should set fusion default version when not configured' () {
         given:
+        SysEnv.push([:])
         def fusionConfig = [enabled: true]
         def config = [fusion: fusionConfig]
         def session = Mock(Session) { getConfig() >> config }
@@ -126,6 +127,7 @@ class SeqeraExecutorTest extends Specification {
 
     def 'should not override fusion version when containerConfigUrl is set' () {
         given:
+        SysEnv.push([:])
         def fusionConfig = [enabled: true, containerConfigUrl: 'https://custom.url/v3.0-amd64.json']
         def config = [fusion: fusionConfig]
         def session = Mock(Session) { getConfig() >> config }