Update to Debian Trixie

This allows us to finally drop all "unstable" hacks (as `riscv64` is an officially supported architecture in Trixie+).

Author: tianon

.github/workflows/ci.yml

@@ -35,7 +35,6 @@ jobs:
         run: |
           strategy="$(GENERATE_STACKBREW_LIBRARY='.github/workflows/fake-gsl.sh' "$BASHBREW_SCRIPTS/github-actions/generate.sh")"
           strategy="$(.github/workflows/munge-build.sh -c <<<"$strategy")"
-          strategy="$(.github/workflows/munge-unstable.sh -c <<<"$strategy")"
 
           EOF="EOF-$RANDOM-$RANDOM-$RANDOM"
           echo "strategy<<$EOF" >> "$GITHUB_OUTPUT"
@@ -65,10 +64,4 @@ jobs:
       - name: '"docker images"'
         run: ${{ matrix.runs.images }}
       - name: Git Diff # see "munge-build.sh"
-        run: |
-          if git diff --exit-code */*/Dockerfile.builder; then # see "hack-unstable.sh" (and "munge-unstable.sh")
-            git diff --exit-code
-          else
-            # for unstable builds, let's leave this in but purely informational (instead of causing CI to fail)
-            git diff
-          fi
+        run: git diff --exit-code

.github/workflows/munge-unstable.sh

@@ -17,27 +17,25 @@ RUN set -eux; \
 		tar \
 	;
 {{ ) else ( -}}
-FROM debian:bookworm-slim
+FROM debian:trixie-slim
 
 RUN set -eux; \
-	apt-get update; \
-	apt-get install -y \
+	apt-get install --update -y \
 		bzip2 \
 		curl \
 		gcc \
 		gnupg \
 		make \
 		patch \
 	; \
-	rm -rf /var/lib/apt/lists/*
+	apt-get dist-clean
 {{ ) end -}}
 {{ if env.variant == "uclibc" then ( -}}
 
 # grab/use buildroot for its uClibc toolchain
 
 RUN set -eux; \
-	apt-get update; \
-	apt-get install -y \
+	apt-get install --update -y \
 		bc \
 		cpio \
 		dpkg-dev \
@@ -49,7 +47,7 @@ RUN set -eux; \
 		unzip \
 		wget \
 	; \
-	rm -rf /var/lib/apt/lists/*
+	apt-get dist-clean
 
 # pub   dsa1024 2009-01-15 [SC]
 #       AB07 D806 D2CE 741F B886  EE50 B025 BA8B 59C3 6319