misc merges @miscmerges@x0f.org

[bitcoin-maintainer-tools] Merged PR from laanwj: check-dnsseeds: Add signet DNS seed https://github.com/bitcoin-core/bitcoin-maintainer-tools/pull/116

[qa-assets] Merged PR from darosior: Some more Script seeds https://github.com/bitcoin-core/qa-assets/pull/79

[qa-assets] Merged PR from duncandean: New coverage for psbt and process_message with libfuzzer https://github.com/bitcoin-core/qa-assets/pull/78

[bitcoin-maintainer-tools] Merged PR from laanwj: list-pulls.py: Minimal support for multi-repository https://github.com/bitcoin-core/bitcoin-maintainer-tools/pull/110

[bitcoin-maintainer-tools] Merged PR from laanwj: Update make-tag.py for new versioning scheme https://github.com/bitcoin-core/bitcoin-maintainer-tools/pull/107

[bitcoin-maintainer-tools] Merged PR from prayank23: Use body as empty string when GitHub API responds with None https://github.com/bitcoin-core/bitcoin-maintainer-tools/pull/113

[packaging] Merged PR from MarcoFalke: snap: Bump to 22.0 https://github.com/bitcoin-core/packaging/pull/71

[qa-assets] Merged PR from agroce: (afl for 2 months) 171 new files with 239 new features added; 4 new c… https://github.com/bitcoin-core/qa-assets/pull/77

[bitcoin-maintainer-tools] Merged PR from laanwj: doc: gitian-keys is now builder-keys https://github.com/bitcoin-core/bitcoin-maintainer-tools/pull/109

[qa-assets] Merged PR from agroce: (eclipser) 103 new files with 160 new features added; 17 new coverage edges https://github.com/bitcoin-core/qa-assets/pull/75

[bitcoin-maintainer-tools] Merged PR from hebasto: Update patches/stripbuildinfo.patch https://github.com/bitcoin-core/bitcoin-maintainer-tools/pull/108

[qa-assets] Merged PR from vasild: add initial input for a newly added test addrman_serdeser https://github.com/bitcoin-core/qa-assets/pull/74

[qa-assets] Merged PR from agroce: (libfuzzer) 1485 new files with 2159 new features added; 89 new coverage edges https://github.com/bitcoin-core/qa-assets/pull/73

[qa-assets] Merged PR from agroce: (eclipser) 88 new files with 142 new features added; 17 new coverage edges https://github.com/bitcoin-core/qa-assets/pull/72

[qa-assets] Merged PR from agroce: More new coverage from Eclipser https://github.com/bitcoin-core/qa-assets/pull/70

[qa-assets] Merged PR from agroce: Another batch of inputs from focused fuzzing https://github.com/bitcoin-core/qa-assets/pull/69

[qa-assets] Merged PR from agroce: More new tests from afl and Eclipser https://github.com/bitcoin-core/qa-assets/pull/68

[btcdeb] Merged PR from kallewoof: test: update catch to 2020-10-08 version https://github.com/bitcoin-core/btcdeb/pull/83

[qa-assets] Merged PR from agroce: First set of new corpus data https://github.com/bitcoin-core/qa-assets/pull/67

[bitcoin-maintainer-tools] Merged PR from hebasto: backport.py expects pulls that are prefixed with repo name https://github.com/bitcoin-core/bitcoin-maintainer-tools/pull/105