[chore](trx-rs): drop redundant CI setup steps for baked runner image

The host-executor runners run jobs inside one container that already has
the Rust toolchain and all build dependencies baked in, so the per-job
`apt-get install` and rustup steps were redundant. Worse, with two jobs
running concurrently in the same runner they collided on the dpkg lock
("Could not get lock /var/lib/dpkg/lock-frontend").

Remove the system-dependency, rustup and cache steps; jobs now run cargo
directly. The cargo registry persists in the long-lived runner container.

Assisted-By: Claude Code (claude-opus-4)
Claude-Session: https://claude.ai/code/session_01NFpGtGTWUEYXLwZeZs2RAV
Signed-off-by: Stan Grams <sjg@haxx.space>

.gitea/workflows/ci.yml

@@ -2,6 +2,11 @@
 #
 # SPDX-License-Identifier: GPL-2.0-or-later
 
+# CI for the self-hosted, host-executor Podman runners (see container/).
+# The runner image bakes in the Rust toolchain and all build dependencies,
+# so jobs go straight to cargo — no apt/rustup setup steps (which also
+# collided on the dpkg lock when jobs ran concurrently in the same runner).
+
 name: CI
 
 on:
@@ -17,86 +22,19 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-
-      - name: Install system dependencies
-        run: |
-          sudo apt-get update
-          sudo apt-get install -y --no-install-recommends \
-            build-essential pkg-config cmake clang libclang-dev \
-            libopus-dev libasound2-dev libsoapysdr-dev
-
-      - name: Set up Rust
-        run: |
-          export PATH="$HOME/.cargo/bin:$PATH"
-          if ! command -v rustup >/dev/null 2>&1; then
-            curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs \
-              | sh -s -- -y --profile minimal
-          fi
-          rustup toolchain install stable --profile minimal \
-            --component rustfmt --component clippy
-          rustup default stable
-
-      - name: Cache cargo
-        uses: actions/cache@v4
-        with:
-          path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-            target
-          key: cargo-${{ runner.os }}-${{ hashFiles('**/Cargo.lock') }}
-          restore-keys: cargo-${{ runner.os }}-
-
       - name: rustfmt
-        run: |
-          export PATH="$HOME/.cargo/bin:$PATH"
-          cargo fmt --all -- --check
-
+        run: cargo fmt --all -- --check
       - name: clippy
-        run: |
-          export PATH="$HOME/.cargo/bin:$PATH"
-          cargo clippy --workspace --all-targets --all-features -- -D warnings
+        run: cargo clippy --workspace --all-targets --all-features -- -D warnings
 
   test:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-
-      - name: Install system dependencies
-        run: |
-          sudo apt-get update
-          sudo apt-get install -y --no-install-recommends \
-            build-essential pkg-config cmake clang libclang-dev \
-            libopus-dev libasound2-dev libsoapysdr-dev
-
-      - name: Set up Rust
-        run: |
-          export PATH="$HOME/.cargo/bin:$PATH"
-          if ! command -v rustup >/dev/null 2>&1; then
-            curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs \
-              | sh -s -- -y --profile minimal
-          fi
-          rustup toolchain install stable --profile minimal
-          rustup default stable
-
-      - name: Cache cargo
-        uses: actions/cache@v4
-        with:
-          path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-            target
-          key: cargo-${{ runner.os }}-${{ hashFiles('**/Cargo.lock') }}
-          restore-keys: cargo-${{ runner.os }}-
-
       - name: Build
-        run: |
-          export PATH="$HOME/.cargo/bin:$PATH"
-          cargo build --workspace --all-targets --locked
-
+        run: cargo build --workspace --all-targets --locked
       - name: Test
-        run: |
-          export PATH="$HOME/.cargo/bin:$PATH"
-          cargo test --workspace --locked
+        run: cargo test --workspace --locked
 
   reuse:
     runs-on: ubuntu-latest