chore: update python version in release.sh

[diegomarquezp]

fixes release workflow:

ERROR: gcloud failed to load. You are running gcloud with Python 3.5, which is no longer supported by gcloud.
Install a compatible version of Python 3.8-3.12 and set the CLOUDSDK_PYTHON environment variable to point to it.

[diegomarquezp]

Tests run: 7, Failures: 2, Errors: 0, Skipped: 0, Time elapsed: 0.087 s <<< FAILURE! - in com.google.cloud.tools.eclipse.appengine.libraries.model.CloudLibrariesInPluginXmlTest
testObjectifyLibraryConfig(com.google.cloud.tools.eclipse.appengine.libraries.model.CloudLibrariesInPluginXmlTest)  Time elapsed: 0.001 s  <<< FAILURE!
java.lang.AssertionError: expected:<6.0.9> but was:<6.1.1>
	at org.junit.Assert.fail(Assert.java:88)
	at org.junit.Assert.failNotEquals(Assert.java:834)
	at org.junit.Assert.assertEquals(Assert.java:118)
	at org.junit.Assert.assertEquals(Assert.java:144)
	at Tests run: 7, Failures: 2, Errors: 0, Skipped: 0, Time elapsed: 0.087 s <<< FAILURE! - in com.google.cloud.tools.eclipse.appengine.libraries.model.CloudLibrariesInPluginXmlTest
testObjectifyLibraryConfig(com.google.cloud.tools.eclipse.appengine.libraries.model.CloudLibrariesInPluginXmlTest)  Time elapsed: 0.001 s  <<< FAILURE!
java.lang.AssertionError: expected:<6.0.9> but was:<6.1.1>
	at org.junit.Assert.fail(Assert.java:88)
	at org.junit.Assert.failNotEquals(Assert.java:834)
	at org.junit.Assert.assertEquals(Assert.java:118)
	at org.junit.Assert.assertEquals(Assert.java:144)
	at