fix: bump alpine 3.24, dynamic python paths in patch.py, tini via apk

- Alpine 3.23 → 3.24 (ships Python 3.14, not 3.12)
- patch.py: use glob + sys.version_info instead of hardcoded python3.12 paths
- Move SSL SECLEVEL=1 sed from Dockerfile into patch.py
- Tini: replace commented-out manual binary download with apk add tini
  (ENTRYPOINT ["/sbin/tini", "--"] as PID 1 for proper signal handling)
- Remove dead TINI_VERSION env and commented-out lines

Dockerfile

@@ -1,27 +1,21 @@
-FROM alpine:3.23
+FROM alpine:3.24
 LABEL maintainer="Cabillot Julien <dockerimages@cabillot.eu>"
 
 COPY entrypoint.sh /entrypoint.sh
 COPY patch.py /tmp/patch.py
 
 # hadolint ignore=DL3018
-RUN apk add --no-cache offlineimap openssl && \
+RUN apk add --no-cache offlineimap openssl tini && \
     adduser -D offlineimap && \
-    # Force SECLEVEL=1 in imaplib2 to allow connecting to servers with weak DH keys (DH_KEY_TOO_SMALL)
-    # This is required because OpenSSL 3.x in Alpine 3.23 defaults to SECLEVEL=2
-    sed -i 's/ctx = ssl.SSLContext(ssl_version)/ctx = ssl.SSLContext(ssl_version)\n                ctx.set_ciphers("DEFAULT:@SECLEVEL=1")/' /usr/lib/python3.*/site-packages/imaplib2/imaplib2.py && \
-    # Patch offlineimap email generator bug for defective messages
+    # Apply post-install patches:
+    #   - UnicodeEncodeError fallback for defective messages (Maildir + IMAP)
+    #   - SSL SECLEVEL=1 in imaplib2 to allow connecting to servers with weak DH keys
+    #     (OpenSSL 3.x defaults to SECLEVEL=2)
     python3 /tmp/patch.py && rm /tmp/patch.py
 
 COPY --chown=offlineimap offlineimaprc.*.tmpl /home/offlineimap/
 
-# Add Tini
-ENV "TINI_VERSION" "v0.16.1"
-#ADD "https://github.com/krallin/tini/releases/download/${TINI_VERSION}/tini" "/tini"
-#RUN chmod +x "/tini"
-#ENTRYPOINT ["/tini", "--"]
-
 USER "offlineimap"
 
-#ENTRYPOINT [ "/entrypoint.sh" ]
-CMD [ "/entrypoint.sh" ]
+ENTRYPOINT ["/sbin/tini", "--"]
+CMD [ "/entrypoint.sh" ]