Remove the add_dummy_commit.sh hack

The new git tests should be enough to check this scenario. We should ideally not be creating dummy commits on CI.

Author: Kobzol

src/ci/docker/host-x86_64/x86_64-gnu-llvm-18/Dockerfile

@@ -59,11 +59,10 @@ COPY scripts/shared.sh /scripts/
 
 ARG SCRIPT_ARG
 
-COPY scripts/add_dummy_commit.sh /tmp/
 COPY scripts/x86_64-gnu-llvm.sh /tmp/
 COPY scripts/x86_64-gnu-llvm2.sh /tmp/
 COPY scripts/x86_64-gnu-llvm3.sh /tmp/
 COPY scripts/stage_2_test_set1.sh /tmp/
 COPY scripts/stage_2_test_set2.sh /tmp/
 
-ENV SCRIPT "/tmp/add_dummy_commit.sh && /tmp/${SCRIPT_ARG}"
+ENV SCRIPT "/tmp/${SCRIPT_ARG}"

src/ci/docker/host-x86_64/x86_64-gnu-llvm-19/Dockerfile

@@ -2,8 +2,6 @@
 
 set -ex
 
-/tmp/add_dummy_commit.sh
-
 ##### Test stage 1 #####
 
 ../x.py --stage 1 test --skip src/tools/tidy

src/ci/docker/scripts/add_dummy_commit.sh

@@ -108,8 +108,6 @@ pr:
   - name: x86_64-gnu-llvm-19
     env:
       ENABLE_GCC_CODEGEN: "1"
-      # We are adding (temporarily) a dummy commit on the compiler
-      READ_ONLY_SRC: "0"
       DOCKER_SCRIPT: x86_64-gnu-llvm.sh
     <<: *job-linux-16c
   - name: x86_64-gnu-tools