Switch Mbed TLS to stable branch

The `development` branch of Mbed TLS will have some API-breaking
changes in the next few months, in preparation for the next major
release (see
https://lists.trustedfirmware.org/archives/list/mbed-tls@lists.trustedfirmware.org/thread/RHZSQLKCBOPDXS7NFKY5FATMTBYV7D5J/).
To avoid breaking fuzzers, temporarily point them at the `mbedtls-3.6`
long-term support branch. We will go back to fuzzing the `development`
branch before the 4.0 release (Mbed-TLS/mbedtls#9071).

Do not change ecc-diff-fuzzer because
https://oss-fuzz-build-logs.storage.googleapis.com/index.html#ecc-diff-fuzzer
shows that its build has been broken since 2024-01-13.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>

projects/bignum-fuzzer/Dockerfile

@@ -28,7 +28,7 @@ RUN apt-get update && apt-get install -y \
 # or a Rust toolchain.
 RUN pip3 install 'pip>=20'
 
-RUN git clone --depth 1 --recurse-submodules -b development https://github.com/Mbed-TLS/mbedtls
+RUN git clone --depth 1 --recurse-submodules -b mbedtls-3.6 https://github.com/Mbed-TLS/mbedtls
 # Install Python packages from PyPI
 RUN pip3 install -r $SRC/mbedtls/scripts/basic.requirements.txt
 

projects/cryptofuzz/Dockerfile

@@ -41,7 +41,7 @@ RUN git clone --depth 1 https://github.com/google/cityhash.git
 RUN git clone --depth 1 https://github.com/randombit/botan.git
 RUN git clone --depth 1 https://github.com/wolfSSL/wolfssl.git
 RUN git clone --depth 1 https://github.com/wolfSSL/wolfsm
-RUN git clone --depth 1 --recurse-submodules -b development https://github.com/Mbed-TLS/mbedtls.git
+RUN git clone --depth 1 --recurse-submodules -b mbedtls-3.6 https://github.com/Mbed-TLS/mbedtls.git
 RUN hg clone https://hg.mozilla.org/projects/nspr
 RUN hg clone https://hg.mozilla.org/projects/nss
 RUN git clone --depth 1 https://github.com/jedisct1/libsodium.git

projects/mbedtls/Dockerfile

@@ -24,7 +24,7 @@ RUN apt-get update && apt-get install -y \
 # or a Rust toolchain.
 RUN pip3 install 'pip>=20'
 
-RUN git clone --recursive --depth 1 -b development https://github.com/Mbed-TLS/mbedtls.git mbedtls
+RUN git clone --recursive --depth 1 -b mbedtls-3.6 https://github.com/Mbed-TLS/mbedtls.git mbedtls
 RUN pip3 install -r $SRC/mbedtls/scripts/basic.requirements.txt
 
 RUN git clone --depth 1 https://github.com/google/boringssl.git boringssl