CPackRPM: avoid a spurious `;` in the `%pre` and other sections with scripts

This was accidentally added by commit 34c8a230 (CPackRPM: add
scriplets tags only if scripts exist, 2021-04-01, v3.21.0-rc1~387^2).

Fixes: #22501
39 jobs for !6415 with fix-issue-22501 in 13 minutes and 39 seconds (queued for 2 seconds)
latest detached
Status Name Job ID Coverage
  Build
passed build:centos6-x86_64 #6028178
cmake build docker linux manual

00:03:52

passed build:fedora34-ninja #6028179
cmake build docker linux linux-3.17 manual

00:02:21

manual build:macos-x86_64-makefiles #6028181
cmake macos shell xcode-12.5 nonconcurrent manual
manual build:macos-x86_64-ninja #6028180
cmake macos shell xcode-12.5 nonconcurrent manual
manual build:windows-vs2019-x64-ninja #6028182
cmake windows shell vs2019 msvc-19.29-16.10 nonconcurrent manual
passed lint:codespell #6028174
cmake build docker linux

00:00:37

passed lint:debian10-iwyu #6028175
cmake build docker linux

00:02:41

passed lint:fedora34-sphinx #6028177
cmake build docker linux linux-3.17

00:05:28

passed lint:fedora34-tidy #6028176
cmake build docker linux linux-3.17

00:05:41

 
  Test
passed test:fedora34-ninja #6028183
cmake docker linux linux-3.17 x11

00:04:17

created test:macos-x86_64-makefiles #6028185
cmake macos shell xcode-12.5 nonconcurrent
created test:macos-x86_64-ninja #6028184
cmake macos shell xcode-12.5 nonconcurrent
created test:windows-vs2019-x64-ninja #6028186
cmake windows shell vs2019 msvc-19.29-16.10 nonconcurrent
 
  Test Ext
passed test:cuda10.2-nvidia #6028189
cmake cuda-rt docker linux

00:01:01

passed test:debian10-ninja #6028187
cmake build docker linux linux-3.17

00:07:31

passed test:fedora34-makefiles #6028188
cmake build docker linux linux-3.17

00:06:07

passed test:fedora34-ninja-multi #6028190
cmake build docker linux linux-3.17

00:02:39

created test:macos-x86_64-xcode #6028191
cmake macos shell xcode-12.5 concurrent
created test:windows-vs2019-x64 #6028192
cmake windows shell vs2019 msvc-19.29-16.10 concurrent
 
  External
passed cdash

passed ghostflow-check-master

passed ghostflow-check-release

passed ghostflow-stager

passed cdash

passed cdash

passed cdash

passed cdash

passed ghostflow-check-master

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager