Increase lifetime of docs:sid:amd64 artifacts

Artifacts generated by the docs:sid:amd64 job need to be retained longer
than for other jobs as they are used for building bind.isc.org contents.
If these artifacts are removed too quickly, pipelines in the pages/bind
GitLab project start failing, preventing content updates from being
published.  Increase lifetime of the relevant job artifacts to prevent
this from happening.
80 jobs for !3088 with michal/increase-lifetime-of-docs-sid-amd64-artifacts in 21 seconds (queued for 31 seconds)
detached
Status Job ID Name Coverage
  Precheck
canceled #700158
amd64 linux
🐞:sid:amd64

00:00:20

canceled #700157
amd64 linux
💾:sid:amd64

00:00:20

canceled #700155
amd64 linux
autoreconf:sid:amd64

00:00:21

passed #700156
amd64 linux
misc:sid:amd64

00:00:18

 
  Build
canceled #700174
amd64 linux
asan:sid:amd64

canceled #700181
amd64 freebsd
clang:freebsd11.3:amd64

canceled #700182
amd64 freebsd
clang:freebsd12.0:amd64

canceled #700183
amd64 libvirt
clang:openbsd6.6:amd64

canceled #700178
amd64 linux
clang:stretch:amd64

canceled #700179
i386 linux
clang:stretch:i386

canceled #700159
amd64 linux
gcc:alpine3.11:amd64

canceled #700173
amd64 linux
gcc:bionic:amd64

canceled #700165
amd64 linux
gcc:buster:amd64

canceled #700160
amd64 linux
gcc:centos6:amd64

canceled #700161
amd64 linux
gcc:centos7:amd64

canceled #700162
amd64 linux
gcc:centos8:amd64

canceled #700171
amd64 linux
gcc:fedora31:amd64

canceled #700163
amd64 linux
gcc:jessie:amd64

canceled #700166
amd64 linux
gcc:sid:amd64

canceled #700168
arm64 linux
gcc:sid:arm64

canceled #700169
i386 linux
gcc:sid:i386

canceled #700164
amd64 linux
gcc:stretch:amd64

canceled #700170
amd64 linux
gcc:tumbleweed:amd64

canceled #700172
amd64 linux
gcc:xenial:amd64

canceled #700185
amd64 windows
msvc:windows:amd64

canceled #700177
amd64 linux
mutexatomics:sid:amd64

canceled #700184
amd64 linux
nolibtool:sid:amd64

canceled #700167
amd64 linux
oot:sid:amd64

canceled #700180
amd64 linux
pkcs11:sid:amd64

canceled #700176
amd64 linux
rwlock:sid:amd64

canceled #700175
amd64 linux
tsan:buster:amd64

 
  Unit
canceled #700200
amd64 linux
unit:asan:sid:amd64

canceled #700206
amd64 freebsd
unit:clang:freebsd11.3:amd64

canceled #700207
amd64 freebsd
unit:clang:freebsd12.0:amd64

canceled #700204
amd64 linux
unit:clang:stretch:amd64

canceled #700186
amd64 linux
unit:gcc:alpine3.11:amd64

canceled #700199
amd64 linux
unit:gcc:bionic:amd64

canceled #700192
amd64 linux
unit:gcc:buster:amd64

canceled #700187
amd64 linux
unit:gcc:centos6:amd64

canceled #700188
amd64 linux
unit:gcc:centos7:amd64

canceled #700189
amd64 linux
unit:gcc:centos8:amd64

canceled #700197
amd64 linux
unit:gcc:fedora31:amd64

canceled #700190
amd64 linux
unit:gcc:jessie:amd64

canceled #700193
amd64 linux
unit:gcc:sid:amd64

canceled #700194
arm64 linux
unit:gcc:sid:arm64

canceled #700195
i386 linux
unit:gcc:sid:i386

canceled #700191
amd64 linux
unit:gcc:stretch:amd64

canceled #700196
amd64 linux
unit:gcc:tumbleweed:amd64

canceled #700198
amd64 linux
unit:gcc:xenial:amd64

canceled #700203
amd64 linux
unit:mutexatomics:sid:amd64

canceled #700208
amd64 linux
unit:nolibtool:sid:amd64

canceled #700205
amd64 linux
unit:pkcs11:sid:amd64

canceled #700202
amd64 linux
unit:rwlock:sid:amd64

canceled #700201
amd64 linux allowed to fail
unit:tsan:buster:amd64

 
  System
canceled #700223
amd64 linux
system:asan:sid:amd64

canceled #700228
amd64 freebsd
system:clang:freebsd11.3:amd64

canceled #700229
amd64 freebsd
system:clang:freebsd12.0:amd64

canceled #700209
amd64 linux
system:gcc:alpine3.11:amd64

canceled #700222
amd64 linux
system:gcc:bionic:amd64

canceled #700215
amd64 linux
system:gcc:buster:amd64

canceled #700210
amd64 linux
system:gcc:centos6:amd64

canceled #700211
amd64 linux
system:gcc:centos7:amd64

canceled #700212
amd64 linux
system:gcc:centos8:amd64

canceled #700220
amd64 linux
system:gcc:fedora31:amd64

canceled #700213
amd64 linux
system:gcc:jessie:amd64

canceled #700216
amd64 linux
system:gcc:sid:amd64

canceled #700217
arm64 linux
system:gcc:sid:arm64

canceled #700218
i386 linux
system:gcc:sid:i386

canceled #700214
amd64 linux
system:gcc:stretch:amd64

canceled #700219
amd64 linux
system:gcc:tumbleweed:amd64

canceled #700221
amd64 linux
system:gcc:xenial:amd64

canceled #700226
amd64 linux
system:mutexatomics:sid:amd64

canceled #700230
amd64 linux
system:nolibtool:sid:amd64

canceled #700227
amd64 linux
system:pkcs11:sid:amd64

canceled #700225
amd64 linux
system:rwlock:sid:amd64

canceled #700224
amd64 linux allowed to fail
system:tsan:buster:amd64

 
  Docs
canceled #700231
amd64 linux
docs:sid:amd64

 
  Postcheck
canceled #700233
amd64 linux
cppcheck:gcc:sid:amd64

canceled #700234
arm64 linux
cppcheck:gcc:sid:arm64

canceled #700232
amd64 linux
scan-build:buster:amd64