.github: run samples workflows on every master push

Both Linux-libretro-common-samples and Linux-samples-tasks had
GitHub Actions "paths:" filters that limited them to runs where
the push included a change to the code they test.  The filters
were overly conservative -- they miss cross-cutting regressions
where a change outside the filtered tree breaks the code under
test through a transitive include, linker resolution, or similar
non-obvious coupling.

Concretely: the libretro-common samples workflow last ran on
commit 0ef2531 and subsequent commits (c72a70d fix, MD5 rename,
etc.) did not trigger it even though some of those changes could
in principle affect libretro-common via shared headers.  A later
libretro-common change that happens to break in combination with
those upstream shifts would surface the failure attributed to the
wrong commit.

Removing the filters means every master push and every PR runs
both jobs.  Cost: each workflow is ~40s wall-clock (libretro-common
samples: Built 12 / Ran 11, samples/tasks: 3 steps).  Added CI
spend is a rounding error for a project with dozens of platform
jobs that take minutes each; the upside is that we never
misattribute a regression to a later commit just because of a
filename-based filter.

  .github/workflows/Linux-libretro-common-samples.yml: -6 lines
  .github/workflows/Linux-samples-tasks.yml:          -12 lines

Local dry-run of both workflows under the exact GHA shell contract
(bash --noprofile --norc -eo pipefail) on current master c72a70d:

  libretro-common:  Built: 12  Ran: 11  Failed: 0
  samples/tasks:    [pass] database_task build
                    [pass] database_task no-args exit=1
                    [pass] archive_name_safety_test

Author: LibretroAdmin

.github/workflows/Linux-libretro-common-samples.yml

@@ -4,15 +4,9 @@ on:
   push:
     branches:
       - master
-    paths:
-      - 'libretro-common/**'
-      - '.github/workflows/Linux-libretro-common-samples.yml'
   pull_request:
     branches:
       - master
-    paths:
-      - 'libretro-common/**'
-      - '.github/workflows/Linux-libretro-common-samples.yml'
   workflow_dispatch:
 
 permissions:

.github/workflows/Linux-samples-tasks.yml

@@ -4,21 +4,9 @@ on:
   push:
     branches:
       - master
-    paths:
-      - 'samples/tasks/**'
-      - 'tasks/task_decompress.c'
-      - 'tasks/task_database.c'
-      - 'tasks/task_database_cue.c'
-      - '.github/workflows/Linux-samples-tasks.yml'
   pull_request:
     branches:
       - master
-    paths:
-      - 'samples/tasks/**'
-      - 'tasks/task_decompress.c'
-      - 'tasks/task_database.c'
-      - 'tasks/task_database_cue.c'
-      - '.github/workflows/Linux-samples-tasks.yml'
   workflow_dispatch:
 
 permissions: