Add exceptiongroup backport

CI/requirements_ci.in

@@ -1,5 +1,6 @@
 bump-my-version==0.32.1
 deptry==0.23.0
+exceptiongroup==1.2.2
 flit==3.10.1
 pip==25.0
 pylint==3.3.4

CI/requirements_ci.txt

@@ -2,7 +2,7 @@
 # This file is autogenerated by pip-compile with Python 3.10
 # by the following command:
 #
-#    pip-compile --generate-hashes --output-file=CI/requirements_ci.txt CI/requirements_ci.in
+#    pip-compile --allow-unsafe --generate-hashes --output-file=CI/requirements_ci.txt CI/requirements_ci.in
 #
 annotated-types==0.7.0 \
     --hash=sha256:1f02e8b43a8fbbc3f3e0d4f0f4bfc8131bcb4eebe8849b8e5c773f3a1c582a53 \
@@ -175,7 +175,9 @@ docutils==0.20.1 \
 exceptiongroup==1.2.2 \
     --hash=sha256:3111b9d131c238bec2f8f516e123e14ba243563fb135d3fe885990585aa7795b \
     --hash=sha256:47c2edf7c6738fafb49fd34290706d1a1a2f4d1c6df275526b62cbb4aa5393cc
-    # via anyio
+    # via
+    #   -r CI/requirements_ci.in
+    #   anyio
 filelock==3.16.1 \
     --hash=sha256:2082e5703d51fbf98ea75855d9d5527e33d8ff23099bec374a134febee6946b0 \
     --hash=sha256:c249fbfcd5db47e5e2d6d62198e565475ee65e4831e2561c8e313fa7eb961435
@@ -491,7 +493,10 @@ wcwidth==0.2.13 \
     --hash=sha256:72ea0c06399eb286d978fdedb6923a9eb47e1c486ce63e9b4e64fc18303972b5
     # via prompt-toolkit
 
-# WARNING: The following packages were not pinned, but pip requires them to be
-# pinned when the requirements file includes hashes and the requirement is not
-# satisfied by a package already installed. Consider using the --allow-unsafe flag.
-# pip
+# The following packages are considered to be unsafe in a requirements file:
+pip==25.0 \
+    --hash=sha256:8e0a97f7b4c47ae4a494560da84775e9e2f671d415d8d828e052efefb206b30b \
+    --hash=sha256:b6eb97a803356a52b2dd4bb73ba9e65b2ba16caa6bcb25a7497350a4e5859b65
+    # via
+    #   -r CI/requirements_ci.in
+    #   flit