Release issue template: restore non-trivial info from removed RELEASE.md

We have dedicated repositories for packages, so this stuff is already
fragmented into visible and invisible. The docs can be fragmented the same
way. But then everything about this repo should be documented in this repo,
too. This just re-adds docs about the publicly visible stuff. Ex. the last
section, but it is easy to miss, so it's here.

.github/ISSUE_TEMPLATE/release.md

@@ -19,3 +19,30 @@ assignees: ''
 - [ ] Create release on GitHub
 - [ ] Update public docs
 - [ ] Announce release
+
+## Update Bundled Windows Dependencies
+
+### Update packages.icinga.com
+
+Add the latest Boost and OpenSSL versions to
+https://packages.icinga.com/windows/dependencies/, e.g.:
+
+* https://master.dl.sourceforge.net/project/boost/boost-binaries/1.82.0/boost_1_82_0-msvc-14.2-64.exe
+* https://master.dl.sourceforge.net/project/boost/boost-binaries/1.82.0/boost_1_82_0-msvc-14.2-32.exe
+* https://slproweb.com/download/Win64OpenSSL-3_0_9.exe
+* https://slproweb.com/download/Win32OpenSSL-3_0_9.exe
+
+### Update Build Server, CI/CD and Documentation
+
+* [doc/21-development.md](doc/21-development.md)
+* [doc/win-dev.ps1](doc/win-dev.ps1) (also affects CI/CD)
+* [tools/win32/configure.ps1](tools/win32/configure.ps1)
+* [tools/win32/configure-dev.ps1](tools/win32/configure-dev.ps1)
+
+### Re-provision Build Server
+
+Even if there aren't any new releases of dependencies with versions
+hardcoded in the repos and files listed above (Boost, OpenSSL).
+There may be new build versions of other dependencies (VS, MSVC).
+Our GitHub actions (tests) use the latest ones automatically,
+but the GitLab runner (release packages) doesn't.