Bump MSRV to 1.75.0

Finally we get the crates.io "sparse" index protocol. This cuts GitLab
CI `cargo build` time from about 5 minutes to about 5 seconds.

Note that since fc904e0 (Bump MSRV to 1.63.0, 2025-08-02), openSUSE Leap
is back in the game with 15.6 and 16. Oh, well.

* Debian "trixie" (stable)
* Ubuntu 24.04

Author: commonquail

.github/workflows/ci.yml

@@ -25,7 +25,7 @@ jobs:
         include:
           - build: msrv
             os: ubuntu-24.04
-            rust: 1.63.0
+            rust: 1.75.0
 
           - build: stable
             os: ubuntu-24.04

.gitlab-ci.yml

@@ -1,7 +1,8 @@
-# https://launchpad.net/rustc
+# https://hub.docker.com/_/rust
+# https://launchpad.net/rustc/+packages
 # https://packages.debian.org/stable/rustc
 # https://software.opensuse.org/package/rust
-image: rust:1.63.0-slim-bullseye # should actually be bookworm
+image: rust:1.75.0-slim-buster # should actually be trixie
 
 rustfmt:
   script:

Cargo.toml

@@ -9,7 +9,7 @@ repository = "https://gitlab.com/mkjeldsen/commitmsgfmt"
 readme = "README.md"
 license = "Apache-2.0"
 edition = "2021"
-rust-version = "1.63.0"
+rust-version = "1.75.0"
 
 [dependencies]
 unicode-segmentation = "1.10.1"