[neon/qt6/qt6-declarative/Neon/release] debian/upstream: Revert "bring back fake signing key"

[Carlos De Maine]

Git commit d3c63789d68b2dac05cfb1f21a7116ecf2778f5d by Carlos De Maine.
Committed on 09/01/2025 at 12:19.
Pushed by carlosdem into branch 'Neon/release'.

Revert "bring back fake signing key"

This reverts commit 4adf8d3c8ff1890bc14df2dc59ac2d116132fd4c

D  +0    -0    debian/upstream/signing-key.asc

https://invent.kde.org/neon/qt6/qt6-declarative/-/commit/d3c63789d68b2dac05cfb1f21a7116ecf2778f5d

diff --git a/debian/upstream/signing-key.asc b/debian/upstream/signing-key.asc
deleted file mode 100644
index e69de29..0000000