docs/misra: fix sphinx-build issues

Fix the following issues:
1. xen/docs/misra/deviations.rst:90: WARNING: Inline interpreted text or
phrase reference start-string without end-string. [docutils]
2. xen/docs/misra/deviations.rst:54: ERROR: Error parsing content block
for the "list-table" directive: uniform two-level bullet list expected,
but row 6 does not contain the same number of items as row 1 (2 vs 3).
* - R2.1
  - Calls to the `__builtin_unreachable()` function inside the expansion of
    the `ASSERT_UNREACHABLE()` macro may cause a function to be marked as
    non-returning. This behavior occurs only in configurations where
    assertions are enabled. To address this, the `noreturn` property for
    `__builtin_unreachable()` is overridden in these contexts, resulting in
    the absence of reports that do not have an impact on safety, despite
    being true positives.
    Xen expects developers to ensure code remains safe and reliable in builds,
    even when debug-only assertions like `ASSERT_UNREACHABLE() are removed.
3. xen/docs/misra/rules.rst:127: WARNING: Inline interpreted text or phrase
reference start-string without end-string. [docutils]

Signed-off-by: Dmytro Prokopchuk <dmytro_prokopchuk1@epam.com>
Reviewed-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

docs/misra/rules.rst

@@ -124,7 +124,7 @@ maintainers if you want to suggest a change.
            they are used to generate definitions for asm modules
          - Declarations without initializer are safe, as they are not
            executed
-         - Functions that are no-return due to calls to the `ASSERT_UNREACHABLE()'
+         - Functions that are no-return due to calls to the `ASSERT_UNREACHABLE()`
            macro in debug build configurations are not considered violations::
 
               static inline bool