fix: don't unpin blocks that may show up again (#1368)

* backend(fix): Early unpin for pruned blocks with no active `BlockRef`

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* backend/tests: Check unpinning only after max_life time

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* backend/tests: Remove unpinning when droped tests

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* backend/tests: Ensure new blocks are not unpinned

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* backend: Add only pruned blocks to unpin hashset and add a test

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* backend: Introduce the `UnpinPolicy`

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* Update subxt/src/backend/unstable/follow_stream_unpin.rs

* backend: Fix clippy

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* Only unpin blocks that have been pruned by the backend

* Fix comments

* Mark initialized and finalized blocks as 'can_be_unpinned' too and tests

* fmt

* tweak a couple more comments

* tidy tests and fix undeterministic check

* Fix wrong names in comments

* tweak another test to focus it a bit more

* clippy

* wee rename of args in a couple of test helpers

* add some logs and simplify submit_transaction in the same way Alex did

* ditch logging again and keep to the experiment pr

* cargo fmt

* reduce CI timeouts to 30mins

* Handle Init and Stop events in submit_transaction too, just in case

---------

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
Co-authored-by: Alexandru Vasile <alexandru.vasile@parity.io>
Co-authored-by: Alexandru Vasile <60601340+lexnv@users.noreply.github.com>

.github/workflows/rust.yml

@@ -159,7 +159,7 @@ jobs:
     tests:
         name: "Test (Native)"
         runs-on: ubuntu-latest-16-cores
-        timeout-minutes: 45
+        timeout-minutes: 30
         steps:
             - name: Checkout sources
               uses: actions/checkout@v4
@@ -189,7 +189,7 @@ jobs:
     unstable_backend_tests:
         name: "Test (Unstable Backend)"
         runs-on: ubuntu-latest-16-cores
-        timeout-minutes: 45
+        timeout-minutes: 30
         steps:
             - name: Checkout sources
               uses: actions/checkout@v4
@@ -219,7 +219,7 @@ jobs:
     light_client_tests:
         name: "Test (Light Client)"
         runs-on: ubuntu-latest-16-cores
-        timeout-minutes: 45
+        timeout-minutes: 30
         steps:
             - name: Checkout sources
               uses: actions/checkout@v4
@@ -246,7 +246,7 @@ jobs:
     wasm_tests:
         name: Test (WASM)
         runs-on: ubuntu-latest
-        timeout-minutes: 45
+        timeout-minutes: 30
         env:
             # Set timeout for wasm tests to be much bigger than the default 20 secs.
             WASM_BINDGEN_TEST_TIMEOUT: 300