Remove version in extends (#19366)

extends expects the package name only.

Cf. #12480.

var/spack/repos/builtin/packages/candle-benchmarks/package.py

@@ -18,7 +18,8 @@ class CandleBenchmarks(Package):
 
     variant('mpi', default=True, description='Build with MPI support')
 
-    extends('python@2.7:')
+    extends('python')
+    depends_on('python@2.7:')
     depends_on('py-theano +gpu', type=('build', 'run'))
     depends_on('py-keras', type=('build', 'run'))
     depends_on('py-matplotlib +image@:2.2.3', type=('build', 'run'))

var/spack/repos/builtin/packages/cram/package.py

@@ -13,6 +13,7 @@ class Cram(CMakePackage):
 
     version('1.0.1', sha256='985888018f6481c3e9ab4f1d1788e25725d8b92a1cf52b1366ee93793614709a')
 
-    extends('python@2.7:')
+    extends('python')
+    depends_on('python@2.7:')
     depends_on('mpi')
     depends_on('cmake@2.8:', type='build')

var/spack/repos/builtin/packages/ibm-databroker/package.py

@@ -32,7 +32,8 @@ class IbmDatabroker(CMakePackage, PythonPackage):
     depends_on('redis@5.0.2:',    type='run')
     depends_on('libevent@2.1.8', type=('build', 'run'))
 
-    extends('python@3.7:',        when='+python')
+    extends('python',             when='+python')
+    depends_on('python@3.7:',     when='+python')
     depends_on('py-setuptools',   when='+python')
 
     patch('fixes_in_v0.6.1.patch', when='@0.6.1')

var/spack/repos/builtin/packages/memsurfer/package.py

@@ -22,7 +22,7 @@ class Memsurfer(PythonPackage):
     variant('osmesa', default=False,
             description='Enable OSMesa support (for VTK)')
 
-    extends('python@3.7:')
+    extends('python')
     depends_on('python@3.7:', type=('build', 'run'))
 
     depends_on('cmake@3.14:', type='build')

var/spack/repos/builtin/packages/talloc/package.py

@@ -17,4 +17,5 @@ class Talloc(AutotoolsPackage):
     version('2.3.0', sha256='75d5bcb34482545a82ffb06da8f6c797f963a0da450d0830c669267b14992fc6')
     version('2.1.9', sha256='f0aad4cb88a3322207c82136ddc07bed48a37c2c21f82962d6c5ccb422711062')
 
-    extends('python@3:')
+    extends('python')
+    depends_on('python@3:')