ci: ensure the registry cache and lockfile are up-to-date

We are caching the CARGO_HOME which includes git repos of
the gtk-rs bindings. Since we don't specify a branch
so it uses the default branch for the ref.

cargo build usually does an update if it has network access,
but its not guaranted or the case for other tools like clippy
which may still point to the stale git snapshot like here:

https://gitlab.freedesktop.org/thaytan/gstreamer-rs/-/jobs/4165449

.gitlab-ci.yml

@@ -37,6 +37,10 @@ stages:
   - "extras"
   - "deploy"
 
+.source_env_anchor: &source_env
+    - source ./ci/env.sh
+    - mkdir .cargo && echo -e "[net]\ngit-fetch-with-cli = true" > .cargo/config
+
 .debian:10:
   variables:
     FDO_DISTRIBUTION_VERSION: 10
@@ -45,8 +49,7 @@ stages:
     # Override the CARGO_HOME variable to force its location
     CARGO_HOME: "${CI_PROJECT_DIR}/.cargo_home"
   before_script:
-    - source ./ci/env.sh
-    - mkdir .cargo && echo -e "[net]\ngit-fetch-with-cli = true" > .cargo/config
+    - *source_env
 
 .debian:10-base:
   extends: .debian:10
@@ -115,6 +118,11 @@ update-nightly:
 .dist-debian-container:
   extends:
   - .fdo.distribution-image@debian
+  before_script:
+    - *source_env
+    # Ensure the cache and the .lockfile are up to date
+    - cargo generate-lockfile
+    - cargo update
   cache:
     key: "gst"
     paths:
@@ -124,18 +132,18 @@ update-nightly:
 
 .img-stable:
   extends:
-    - .dist-debian-container
     - .debian:10-stable
+    - .dist-debian-container
 
 .img-1-40:
   extends:
-    - .dist-debian-container
     - .debian:10-1-40
+    - .dist-debian-container
 
 .img-nightly:
   extends:
-    - .dist-debian-container
     - .debian:10-nightly
+    - .dist-debian-container
 
 # GST_PLUGINS_RS_TOKEN is a variable of type 'Var' defined in gstreamer-rs CI
 # settings and containing a gst-plugins-rs pipeline trigger token
@@ -205,10 +213,10 @@ plugins-update-nightly:
             FEATURES=v1_18
           fi
 
-          cargo build --color=always --manifest-path $crate/Cargo.toml --features=$FEATURES
+          cargo build --locked --color=always --manifest-path $crate/Cargo.toml --features=$FEATURES
           G_DEBUG=fatal_warnings cargo test --color=always --manifest-path $crate/Cargo.toml --features=$FEATURES
         else
-          cargo build --color=always --manifest-path $crate/Cargo.toml
+          cargo build --locked --color=always --manifest-path $crate/Cargo.toml
           G_DEBUG=fatal_warnings cargo test --color=always --manifest-path $crate/Cargo.toml
         fi
       done
@@ -217,8 +225,8 @@ plugins-update-nightly:
       # tutorials/examples with all features
     - |
       if [ -n "$ALL_FEATURES" ]; then
-        cargo build --color=always --manifest-path examples/Cargo.toml --bins --examples --all-features
-        cargo build --color=always --manifest-path tutorials/Cargo.toml --bins --examples --all-features
+        cargo build --locked --color=always --manifest-path examples/Cargo.toml --bins --examples --all-features
+        cargo build --locked --color=always --manifest-path tutorials/Cargo.toml --bins --examples --all-features
       fi
 
 test 1.40:
@@ -281,12 +289,12 @@ clippy:
           FEATURES=v1_18
         fi
 
-        cargo clippy --color=always --manifest-path $crate/Cargo.toml --features=$FEATURES --all-targets -- -A clippy::redundant_pattern_matching -A clippy::single_match -A clippy::cast_lossless -A clippy::missing_safety_doc -D warnings
+        cargo clippy --locked --color=always --manifest-path $crate/Cargo.toml --features=$FEATURES --all-targets -- -A clippy::redundant_pattern_matching -A clippy::single_match -A clippy::cast_lossless -A clippy::missing_safety_doc -D warnings
       done
     # And also run over all the examples/tutorials
     - |
-      cargo clippy --color=always --manifest-path examples/Cargo.toml --all-targets --all-features -- -A clippy::redundant_pattern_matching -A clippy::single_match -A clippy::cast_lossless -A clippy::missing_safety_doc -D warnings
-      cargo clippy --color=always --manifest-path tutorials/Cargo.toml --all-targets --all-features -- -A clippy::redundant_pattern_matching -A clippy::single_match -A clippy::cast_lossless -A clippy::missing_safety_doc -D warnings
+      cargo clippy --locked --color=always --manifest-path examples/Cargo.toml --all-targets --all-features -- -A clippy::redundant_pattern_matching -A clippy::single_match -A clippy::cast_lossless -A clippy::missing_safety_doc -D warnings
+      cargo clippy --locked --color=always --manifest-path tutorials/Cargo.toml --all-targets --all-features -- -A clippy::redundant_pattern_matching -A clippy::single_match -A clippy::cast_lossless -A clippy::missing_safety_doc -D warnings
 
 deny:
   extends: .img-stable
@@ -302,7 +310,7 @@ gir-checks:
   script:
     - git clone --depth 1 https://github.com/gtk-rs/checker
     - cd checker && echo '[workspace]' >> Cargo.toml
-    - cargo build --release
+    - cargo build --locked --release
     - |
       cargo run --release -- \
         --gir-file ../Gir_GstApp.toml ../gstreamer-app \